ADOLESCENT AND ADULT PERSONALITY AND RELATIONSHIP FACTORS AS PREDICTORS OF ADULT ROMANTIC RELATIONSHIP QUALITY

Family, friendship, and romantic relationships are considered to be the most important close relationships in one’s life (Demir, 2010). The current study sought to examine the role of adolescent and adult personal (personality) and interpersonal (relationships with parents and peers) factors as predictors of adult romantic relationship quality. The study also aimed to examine the association between personality and relationship factors and the absence or presence of a romantic relationship in adulthood. The data for this study came from the National Longitudinal Study of Adolescent to Adult Health (Add Health), which is a 12-year, 4-wave, longitudinal study. The sample included 1,929 participants who took part in Wave I and Wave IV of the study. Linear regression was utilized to examine the relationship between adolescent and adult personality and relationship factors and romantic relationship quality in adulthood, and to compare the strength of adolescent and adult predictors. Results revealed that adolescent factors were stronger predictors of adult romantic relationship quality, with adolescent conscientiousness being the strongest predictor amongst variables. Logistic regression was also used to determine the association between personality and relationship factors and relationship status. Findings indicate that a better-quality relationship with an individual’s mother during adolescence and higher levels of extraversion in adulthood, increased the likelihood of being in a romantic relationship in adulthood. The results of this study contribute to the limited amount of existing literature concerning adolescent and adult personality and relationship factors impact on romantic relationship quality in adulthood.


LIST OF TABLES
Family structures are currently changing as cohabitation is on the rise, more adults are delaying marriage, and a growing share of children are living with single or unmarried parents (Pew Research Center, 2020). The decline in marriage rates is associated with the increase in unwed childrearing (Brown, 2020). In 2018, the Pew Research Center estimated about one-third of children in the U.S. are living with an unmarried parent.
These trends could be due to a lack of high-quality relationships or nonnormative relationships, such as single mothers by choice, which may lead individuals to miss out on the benefits of these relationships. The presence of a high-quality romantic relationship has been linked to lower levels of anxiety and depression, as well as better health, longer life expectancy, and better parenting practices (Vanorman & Scommenga, 2016;Allen et al., 2020). In efforts to shift these statistics, predictors of adult romantic relationships should be identified.
An individual develops many relationships over the lifespan, however, one of the first and most prominent relationships is between a parent and the child. Bowlby's Attachment Theory (1969) posits how the quality of relationships during the early years of life can have a direct impact on the quality of future relationships. The majority of research on parent-child relationships primarily assesses the parent-child relationship early in life and how it can impact adolescent outcomes (Johnson & Galambos, 2014).
However, as children grow up, they tend to be less involved in their relationship with their parents. Johnson and Galambos (2014) found a direct link between adolescent parent-child relationships and young adult romantic relationship quality, showing that higher levels of relationship quality with parents during adolescence is correlated with higher levels of romantic relationship quality in adulthood. It is unknown if adult parentchild relationships can be an important factor when predicting adult romantic relationship quality.
Although early childhood and adolescent experiences are important to look at as predictors of adult romantic relationship quality, concurrent adult experiences may be just as influential due to the developmental changes, such as beliefs, values, and behaviors, that continue to take place over the life span (Allen et al., 2020). It is hypothesized that the factors influencing adolescent romantic relationships will influence adult romantic relationships.
Other potential correlates of adult romantic relationship quality include relationships with peers and personality types. A study reported adolescents who describe having positive relationships with their friends are more likely to have higher quality adolescent romantic relationships (Kochendorfer & Kerns, 2017). This study investigated adolescent parent-child relationship quality and adolescent friendship quality, finding that although parent-child relationships may predict involvement for romantic relationships during adolescence, friendship predicts the quality of these romantic relationships (Kochendorfer & Kerns, 2017). Though, it is unknown if the quality of friendships has the same impact during adulthood.
In addition to peers, personality can also impact quality and satisfaction within romantic relationships (Demir, 2007). Existing literature has shown that personality traits from the Big Five framework (extroversion, neuroticism, agreeableness, openness, and conscientiousness) are related to romantic relationship outcomes during college, such as quality and satisfaction (Demir, 2007).
It is important to acknowledge those who do not partake in the "traditional" romantic relationship, which is often between two individuals. For example, in recent years there has been a rise in the number of women who choose to have a child without the involvement of a partner (Jadva et al., 2009). This group of women is often referred to as "single mothers by choice" as they become mothers in a number of ways, including sperm donation. Relationship status may not be related to romantic relationship quality for these mothers as they have chosen not to be in one. A study done by Jadva et al. (2009) found that the majority of participants stated the main reason they become a single mother by choice is because they were ready to join motherhood.
The current research identifies the predictors of adult romantic relationship quality, exploring factors including adolescent parent-child relationships, adolescent personality characteristics, adolescent peer relationships, adult parent-child relationships, and adult peer relationships. This research also compares whether adolescent or adult factors are stronger predictors of adult romantic relationship quality. Lastly, this study observes the association between personality and relationships with peers and parents (adolescent and adult) to the presence or absence of romantic relationship in adulthood.

REVIEW OF LITERATURE
There are many indicators of a positive romantic relationship. A positive romantic relationship can be defined as one where both partners express warmth, such as loving gestures, structure and roles in the relationship, stability, such as focusing on the positives more than negatives of the relationship, and autonomy support, which encourages each partner to be true to themselves (Zimmer-Gembeck & Ducat, 2010). Romantic relationships have been explicitly identified as being correlated to an individual's subjective well-being (Kansky, 2018). Traditionally, the most common markers of a positive romantic relationship are high relationship satisfaction, commitment, intimacy, trust, passion, and love (Demir, 2007). Current research has found that relationship quality is positively correlated with well-being, meaning those who report higher quality relationships also report higher levels of happiness and life satisfaction (Kansky, 2018).
Low-quality romantic relationships are associated with individuals reporting lower levels of well-being (Hudson, Lucas, & Donnellan, 2020). Those in shorter romantic relationships often report lower levels of agreement regarding romantic behaviors, whereas couples who report higher levels of agreement regarding romantic behaviors are typically in longer relationships (Zimmer-Gembeck & Ducat, 2010).
A study by Jeon and Neppl (2019) supports the impact of positive romantic relationships, by studying the transmission of harsh parenting behavior across three generations. This study followed (generation one/G1) mothers and their children (generation two/G2) from adolescence to adulthood. When the child (G2) was in adulthood, researchers studied the adult child's (G2) romantic partners and their children (generation three/G3). Results indicated that a positive G2 romantic partner is associated with lessening the intergenerational transmission of externalizing parenting behaviors, such as harsh parenting (Jeon & Neppl, 2019).
Recent literature has also found that relationship status is important when looking at an individual's well-being. Gomez-Lopez, Viejo, and Ortega-Ruiz (2019) conducted a systematic review on the current literature regarding the association between romantic relationships and well-being in adolescence and emerging adulthood. Gomez-Lopez et al. (2019) found that young adults who have romantic relationships are happier, feel more satisfied with their lives, have fewer problems with mental and physical illness, show greater positive affect, and have better levels of self-esteem compared to those who are not in relationships.

Parent-Adolescent Relationship
A hypothesized predictor of adult romantic relationships is the parent-child relationship. Attachment theory (Bowlby, 1969) theorizes that although nearly all children become attached to their caregiver, it is the quality of that attachment that can predict developmental issues (Van Rosmalen, Van der Veer, & Van der Horst, 2015). Bowlby (1969) presumes that the relationships formed in the early stages of life between a child and their parent have a large impact for the duration of the child's life regarding how he/she reasons, feels, and acts in close relationships. Further research has provided evidence to support Bowlby's Attachment Theory. Interpersonal experiences in early life have been shown to predict how individuals will act in future romantic relationships. The Minnesota Longitudinal Study (Simpson, Collins, & Salvatore, 2011) followed 75 participants starting at 12 months of age to 23 years old. Researchers found that important adult romantic outcomes, including stability and satisfaction in relationships and the ability to resolve and recover from conflict, are related to early relationship experiences, such as better relationship quality with caregivers. Similarly, a longitudinal study by Zayas, Mischel, Shoda, and Aber (2011) studied 36 participants from 18 months to 22 years old. Study results found that sensitive maternal caregiving in early life predicts less avoidance and anxiety in adult romantic relationships (Zayas et al., 2011).
Interpersonal experiences in adolescence, defined as ages 10-19 by the World Health Organization (WHO, 2021), also can impact how adults regulate their emotions in their romantic relationship (Simpsons et al., 2011). Johnson and Galambos (2014) explored how the quality of parent-adolescent relationships is directly related with the quality of romantic relationships in young adulthood, which ranges between the ages of 25-32 years old (Johnson & Galambos, 2014). In this study, parent-adolescent relationship quality was measured through self-report measure, with both the parent and adolescent participants (n=2,970) responding. The self-report measure included questions such as "How close do you feel to your mother/father?" and "Is your mother/father warm and loving towards you?". Young adult romantic relationship quality was also measured through a self-report measure that only adult children answered. Results from this study found that parent-adolescent relationship quality, such as communication and conflict resolution, directly predicts adult romantic relationship quality 15 years later (Johnson & Galambos, 2014). Johnson and Galambos (2014) found that high quality parentadolescent relationships predicted high quality romantic relationships in young adulthood, and low-quality parent-adolescent relationships predicted less success in romantic relationships.
Positive parenting during adolescence is associated with better problem-solving skills and less violence in young adult romantic relationships (Xia, Fosco, Lippold, & Feinberg, 2018). Xia et al. (2018) evaluated 975 individuals at age 12 and again at age 19. Adolescents who reported positive parenting in adolescence also reported better problem-solving skills and less risk for violence within a relationship. In addition to problem-solving skills and violence, young adults who reported that they engage positively with their family also reported stronger feelings of love within their current romantic relationship (Xia et al., 2018).
In contrast, adolescents engaging in lower-quality relationships with parents or partners, such as relations with high levels of conflict, can develop a negative representation of relationships. This leads to an increased probability of future unhealthy romantic relationship patterns, which can negatively impact psychosocial functioning over time (Kanksy & Allen, 2018).

Parent-Adult Child Relationships
Although many studies have explored parent-child relationships in general, less is known about the impact of parent-child relationships during adulthood on romantic relationship quality. Adulthood has been defined as the time after the individual has gone through their early 20's (Johnson & Galambos, 2014). Previous studies have mainly explored measures of adult attachment styles (La Valley & Guerrero, 2012;Kochendofer & Kerns, 2017;Dillow et al., 2014) but these do not measure the current parent-child relationship. For example, Dillow, Goodboy, and Bolkan (2014) were interested in seeing how adult attachment styles can influence romantic relationships across the lifespan.
Their results from a questionnaire administered to 173 individuals ranging from the ages of 19 to 52 years, found that those with an avoidant attachment style reported weaker feelings towards romance and love (Dillow et al. 2014). La Valley and Guerrero (2012) examined the associations between adult attachment and relational satisfaction in adult child-parent relationships. Results from a participant self-report measure concluded that relationship satisfaction in adult children was positively associated with positive adult child-parent attachment styles (La Valley & Guerrero, 2012). These results support the idea that higher quality adult parent-child relationships have the potential to predict higher adult romantic relationship quality.

Individual Personality Characteristics
As individuals differ in individual characteristics, such as personality, so does their romantic relationship quality (Yu, Branje, Keijers, & Meeus, 2014). Yu et al. (2014) sought to examine the relationship between different personality types and romantic relationship quality in emerging adulthood. Researchers studied 424 participants personality styles at age 12 and their romantic relationship quality at age 21. Results from the longitudinal study posits that individual characteristics, such as personality type, can play an important role in the ongoing quality of relationships with romantic partners (Yu et al., 2014). Specifically, participants categorized as "under controllers", who have a high level of ego control, or "over controllers", who have a low level of ego control, experienced lower quality romantic relationships compared to those who are "resilient", who have high levels within all of the Big 5 personality factors. Demir (2007) also found a difference in quality of romantic relationships when comparing personality styles. Of the Big Five personality traits, research found that extraversion and agreeableness were related with positive romantic relationship quality, whereas neuroticism and openness were related to negative romantic relationship quality (Demir, 2007). Additional research that examines adolescent personality characteristics also found a significant relationship to young adult romantic relationship quality (Parker et al., 2012;Yu et al., 2014;Masarik et al., 2012). Although unknown, these findings give reason to believe that adult individual characteristics will be related to the quality of adult romantic relationships.
The present study adds to the literature by examining the impacts of personality characteristics on romantic relationship quality from ages 24 to 32.

Peer Relationships and Adult Romantic Relationships
Although no available research investigates the association between adult peer relations and adult romantic relationships, some research has shown that adolescents who have high quality friendships, for example friendships with high levels of trust and low levels of conflict, are more likely to have higher quality romantic relationships (Kochendorfer & Kerns, 2017). Further, research suggests that peers may serve as a functioning model for romantic relationships (Reitz, Zimmermann, Hutteman, Specht, & Nyer, 2014). Reitz et al. (2017) sought to examine the role of peer relationships in personality development over the lifespan. From childhood to young adulthood, peer relationships were found to be important indicators of how individuals may engage in romantic relationships in the future. Specifically, positive peer relationships predict higher-quality romantic relationships (Reitz et al. 2017). Considering the omnipresence of peer relationships, this study will look at peer relationships in adolescence and adulthood and their association with romantic relationship quality in adulthood.
The present study addresses gaps in the literature by examining the association between peer relationships, parent-child relationships, personality characteristics, and adult romantic relationship quality. The present investigation extends research by comparing the influence of adolescent interpersonal relationships to adult interpersonal relationships and their impact on adult romantic relationship outcomes. Furthermore, this study extends beyond interpersonal relationships by looking at personality components and how they may relate to romantic relationship quality in adulthood.

Procedure
The present study uses data from Waves I and IV of the National Longitudinal Study of Adolescent to Adult Health (Add Health). Add Health is a longitudinal study of a nationally representative sample of United States adolescents who were in grades 7-12 during the 1994-95 school year. Participants took part in one in-school questionnaire during Wave I, and four in-home interviews between all four waves. Wave I data collection took place between September 1994 and December 1995. For Wave I, the inschool sample was a stratified, random sample of all high schools in the United States. A school was eligible for the sample if it included an 11th grade and had a minimum enrollment of 30 students. The in-school questionnaire was administered to more than 90,000 students in grades 7 through 12. Researchers used a computer-assisted personal interview (CAPI)/audio computer-assisted self-interview (ACASI) to collect data.
The Wave I in-home interview sample of 27,000 adolescents consisted of a core sample from each community, plus selected special over samples. Wave IV is the most recently conducted in-home interview which took place in 2008 when participants ranged from 24 to 32 years old. Add Health combines data on participants' social, economic, psychological, and physical well-being with contextual data regarding the family, neighborhood, community, school, friendships, peer groups, and romantic relationships.
All Wave I respondents were eligible for in-home interviews at Wave IV. Wave I consisted of over 90,000 participants in grades 7 through 12, when the majority of participants ranged from 10 to 19 years old. The study obtained information regarding social and demographic characteristics of respondents, as well as education and occupation of parents, information on household structure, expectations for future, selfesteem, health status, risk behaviors, friendships, and school-year extracurricular activities. Wave IV in-home interviews consisted of 5,114 participants and was conducted when the original Wave I respondents were 24 to 32 years old. Data were collected on the social, economic, psychological, and health circumstances of respondents. Survey questions were expanded in Wave IV to include emotional content and quality of current relationships and maltreatment during childhood by caregivers.
Add Health participants provided written informed consent for participation in all aspects of Add Health in accordance with the University of North Carolina School of Public Health Institutional Review Board guidelines.

Sample
The present study sample excluded participants who did not provide data for the independent or dependent variables of interest. Thirty-seven percent of the original sample (n=5,114) were able to provide data for all variables (n=1929). Participants in the final sample were about half male (49%) and half female (50%). Participants included in the study were predominately White (68%) and received at least some college education (70%). Of those included in the sample, more than half (80%) had an average yearly income of more than $30,000. Table 1 presents baseline demographic differences between those who are in the study and those who were excluded. The analyses showed that participants in the study were more advantaged and differed significantly from those who were excluded in several areas. Participants included in the study were more likely to be White than those who were excluded, while those who were excluded were more likely to be African American than participants who were included in the study (p <.000). Those who were excluded from the study were more likely to have parents with less than a college education compared to those who were included (p <.000). Similarly, those who were excluded were also more likely to have less than a college education (37%) compared to participants included in the study (p <.000). Individuals in the study were more likely to have an average income of over $100,000, whilst individuals who were not in the study were more likely to have an average income of less than $29, 999 (p <.000). Also, those who were excluded from the study, on average, had a slightly larger household size compared to those in the final sample (p =.002).

Parent-Adolescent Relationship Quality
Based on a previous study by Johnson and Galambos (2014) that uses Add Health data, four items from Wave I were used to assess the relationship between adolescents, who ranged from 12 to 19 years old, and their parents. The interview assessed the quality of the participant's relationship with both their mother and father using the following questions: (1) How close do you feel to your mother/father? (2) Most of the time your mother/father is warm and loving toward you (3) You are satisfied with the way your mother/father communicates with you, and (4) Overall, you are satisfied with your relationship with your mother/father. For the first question responses ranged from 1-not at all, to 5 -very much. For the following questions, responses ranged from 1-strongly agree, to 5 -strongly disagree. Mean scores of responses were calculated to create each scale, with higher scores indicating better relationship quality. Cronbach's alpha was .86 for the items regarding the adolescent-mother relationship quality, and .90 for the fatheradolescent relationship quality.

Adolescent Personality Characteristics
In Wave 1, adolescents were asked interview questions regarding themselves.
Young and Beaujean (2011)  usually try to think of as many different ways to approach the problem as possible, (3) When making decisions, you generally use a systematic method for judging and comparing alternatives, and (4) After carrying out a solution to a problem, you usually try to analyze what went right and what went wrong. Responses ranged from 1 -strongly agree, to 5 -strongly disagree. The scores from these items were summed together to create a scale for each of the three personality styles. Higher scores indicated higher levels of the specific personality type. Reliability of these scales were α=.86 for neuroticism, and α=.76 for extraversion and conscientiousness.

Adolescent Peer Relationships
In Wave 1, adolescents responded to five questions regarding friendships.
Participants were asked whether or not they engaged in the following activities with their friend in the past week: (1) Go to friend's house, (2)

Parent-Adult Child Relationship Quality
In Wave 4, participants assessed their relationship quality with their parents as adults, when original participants were 25-32 years old. In a previous study with the Add Health dataset, two items were used to assess participant's relationship with their parents.
The mean scores from the following items were averaged to create the scale, with higher scores indicating better relationship quality and lower scores indicating lower relationship quality. Participants answered the following questions regarding both their mother and father: (1) How close do you feel to your mother/father? (2) You are satisfied with the way your mother/father communicates with you. Responses ranged from 1-not at all close, to 5-very close, and 1-strongly disagree, to 5-strongly agree. Cronbach's alpha reliability for these scales was .73

Adult Personality Characteristics
Young and Beaujean (2011)  Lastly, conscientiousness was measured using four items: (1) I get chores done right away, (2) I often forget to put things back in their proper place, (3) I like order, and (4) I make a mess of things. Participants were asked how much they agreed with the previous statements regarding themselves. Responses ranged from 1, strongly agree, to 5, strongly disagree. The scores from these items were summed together. Reliability for these scales were α=.86 for neuroticism, and α=.76 for extraversion and conscientiousness.

Adult Peer Relationships
To measure quantity of peers, participants were asked to report the number of close friends they have. Responses included (1) none, (2) 1 or 2 friends, (3) 3 to 5 friends, (4) 6 to 9 friends, or (5) 10 or more friends.

Relationship Quality
The current study used adult romantic relationship quality as the primary dependent variable. Adult romantic relationship data comes from Wave 4 of the Add Health data. Previously, a seven-item omnibus measure was constructed to assess participant romantic relationship quality as adults (Johnson & Galambos, 2014).
Respondents indicated their feelings towards their relationships using the following questions: (1) We enjoy doing even ordinary, day to day things together, (2) I am satisfied with the way we handle our problems and disagreements, (3) I am satisfied with the way we handle finances (4) My partner listens to me when I need someone to talk to,

Relationship Status
Data concerning whether or not participants were in a romantic relationship came from Wave 4 of the Add Health data. Participants were asked to report the number of people they were currently involved in a romantic or sexual relationship with. For the exploratory analysis, participants who reported being in a romantic or sexual relationship with at least one person were considered to be "in a relationship."

Demographic Covariates
Demographic data came from both Wave I and Wave IV of the Add health study.
Wave I provided demographics regarding participant's parents (income and education level) and Wave IV provided demographics for participants (age, race, income, gender, primary language, education level, income level, and household size). A few demographic variables were recoded to have fewer categories for the purpose of the study. Participant's education level was originally reported in 13 groups and was recoded into high school/vocational training or less and some college or more. Parent's education level was originally reported in 10 groups and was recoded into high school/vocational training or less and some college or more. The race variable was recoded into three groups, White, African American, and other. Lastly, participant's income was initially described in 12 groups and was recoded into three groups, less than $29,999, in between $30,000 and $99,999, and more than $100,000. Gender, age, primary language, parent's income, and household size kept their original coding.

Analyses
Statistical analyses were conducted using SPSS Version 26. Prior to main analyses, frequencies and descriptive statistics of demographics and variables of interest were conducted to identify participants with missing data and aid in determining which variables needed to be recoded for analyses. Reliability analysis was used to test Cronbach's alpha of new and previously created scales. Chi-square and t-tests were then used to test for significant differences between those who were included and excluded from the study to help describe findings. Chi-squares and t-tests were also used to identify significant relationships between demographics and participants' relationship status. Bivariate correlations were conducted between independent variables before indepth analyses to determine if multicollinearity needed to be controlled for. Lastly, bivariate correlations between independent variables and romantic relationship quality were conducted to identify significant predictors prior to running regressions.
To address the first and second aim of the study, identifying significant predictors An exploratory analysis was also conducted to determine if the presence or absence of a romantic relationship was associated with any independent variables.
Logistic regression was utilized for the exploratory analysis where relationship status (in/out) is the dependent variable and personality and relationships with peers/parents are the independent variables.

FINDINGS
Demographic differences between those who were in a relationship at the time of the study (18.5%) and those who were not in a relationship (81.5%) are presented in Table 2. Overall, the results suggest that the two groups are quite different. More males reported being in a relationship compared to females (p= .008). The vast majority of participants who were in a relationship speak English as their primary language. Chisquare results showed a significant relationship between race and relationship status (p=.000) as the percentage of White individuals not in a relationship (71%) was higher than those in a relationship (55%). Further, more than a quarter of individuals who were in a relationship reported being African American (29.4%), compared to not being in a relationship where only 15% reported being African American. Participants who were not in a relationship were more likely to have an average income of $100,000 or more (19.1%) compared to those who were in a relationship (12.7%). Furthermore, those who reported being in a relationship were more likely to have an average income of less than $29,999 (28.1%) compared to those who were not in a relationship (18.2%). Participants who were in a relationship and their parents were both significantly more likely to have some college educational experience compared to participants who were not in a relationship and their parents (p< .000). An independent samples t-test also showed a significant relationship between parent's income and participant's relationship status (p=.044). Parental income was on average $9,000 higher for those who were in a relationship compared to those who were not in a relationship (p=.026). indicates a multicollinearity problem (Abu-Bader, 2011). Results from the correlation are presented in Table 3. The strongest correlation was between Adolescent Neuroticism and Mother-Adolescent relationship quality (r=.39, p<.01), indicating that higher neuroticism during adolescence is associated with better relationship quality with their mother. All other correlations were less than .38, indicating all correlations are either weak or very weak. Therefore, multicollinearity is not a problem for these variables as all correlations are less than .80.  Table 4. Correlations that are not significant were not included in primary regression analyses. Nine of the correlations were statistically significant and less than or equal to .69. Five of the nine significant correlations were adolescent factors.
The strongest correlation was between adolescent extraversion and adult romantic relationship quality at the moderate level (r = .69, p < .01). This relationship shows that higher levels of extraversion during adolescence is associated with higher romantic relationship quality during adulthood. Results from correlations showed significant (p < .05) positive relationships between all adolescent predictor variables, except adolescent peer score which had a non-significant negative correlation. Four of the five adult factors were significantly associated with adult romantic relationship quality. Adult extraversion (r = -.046, p < .05), parent-adult child relationship quality (r = -.045, p < .051), and number of friends in adulthood (r = -.97, p < .01), all produced a significant negative result, signifying that an increase in these areas is correlated with a decrease in romantic relationship quality during adulthood. Lastly, adult conscientiousness showed a significant positive correlation (r= .047, p < .05) which demonstrates that greater scores of conscientiousness during adulthood is associated with higher scores of adult romantic relationship quality. p < .05*, p <.01**, p <.001*** Linear regression was conducted to estimate a regression model that best predicts adult romantic relationship quality from the nine factors: adolescent neuroticism, conscientiousness, and extraversion, adult extraversion and conscientiousness, mother and father-adolescent relationship quality, parent-adult child relationship quality, and number of friends in adulthood, while controlling for significant demographic variables (gender, race, education, income). Results of the regression ( Table 5 (Table 6) were statistically significant χ 2 (8) = 29.99, p < .000.
After controlling for demographic variables, results showed that higher levels of motheradolescent relationship quality are associated with an increased likelihood of being in a relationship (B=.223), but higher levels of extraversion (B=-.088) and only having 1-2 friends (B=-1.107) in adulthood decreased the likelihood of being in a relationship.

DISCUSSION
This study explored personality factors and relationships with parents and peers as predictors of romantic relationship quality in adulthood. Findings from a linear regression show that adolescent conscientiousness was the strongest significant predictor of adult romantic relationship quality, indicating that higher levels of conscientiousness during adolescence is associated with higher levels of romantic relationship quality in adulthood.
In addition to adolescent conscientiousness, higher levels of relationship quality with parents during adolescence, and higher levels of conscientiousness during adulthood also emerged as significant positive predictors of higher levels of adult romantic relationship quality. Findings from the linear regression also indicate that adolescence is a crucial time period when looking at predictors of adult romantic relationship quality.
The results of this study found that adolescent conscientiousness was the strongest predictor of romantic relationship quality in adulthood. Adult conscientiousness emerged as the fourth significant predictor of adult romantic relationship quality.
Conscientiousness has been defined as the tendency to follow social norms for impulse control, to be goal directed, to plan, and to be able to delay gratification (Roberts et al., 2009). Existing literature suggests that adults with higher levels of conscientiousness can manage the conflicts developed cohesively in the relationships in a more constructive manner (Maleki et al., 2019). This finding was somewhat surprising as a previous study that explored personality types and romantic relationship quality did not find conscientiousness to be a significant predictor of quality but did find it to be a significant predictor of overall happiness. This discrepancy could be due to the fact that the current study did not utilize all five personality factors, causing conscientiousness to have a greater effect (Demir, 2007).
The second and third strongest predictors of adult romantic relationship quality were participant's relationships with their mother and father, respectively, during adolescence. Previous research examining relationship outcomes in adulthood also found relationships with parents during adolescence to be an important factor for predicting romantic relationship quality and satisfaction (Lee, 2018;Cui et al., 2016;Picci et al., 2019). In a longitudinal study by Picci et al. (2019), researchers found that parentadolescent conflict was associated with an increase in negativity within romantic relationships in adulthood. One study looking at the effect of divorce on child's romantic relationships, found that daughters who reported more negative relationships with fathers also reported lower relationship quality, but not sons (Lee, 2018). Cui, Gordon, and Wickrama (2016) also used Add Health data in their study examining the role of mother's relationship history on adult's romantic relationship experiences. Researchers found that decreased adolescent-mother closeness is associated with children engaging in more and shorter romantic relationships, but not necessarily in the quality of them.
This research also compared whether adolescent or adult factors were stronger predictors of adult romantic relationship quality as much of the existing literature looks mainly at adolescent factors as indicators for adult outcomes (Hair et al., 2008;Seiffge-Krenke et al., 2010). Results found that adolescent personality and relationship factors accounted for three times the amount of the variance in adult romantic relationship quality compared to adult personality and relationship factors, which only accounted for .4% of the variance. It is possible that parent-adult child relationships did not emerge as significant predictors of romantic relationship quality as they were measured with two items. Parent-adolescent relationship quality was measured with two times the number of items, which allows for greater validity of the content being measured. These findings also support the importance of adolescent relationships and experiences as they pertain to outcomes in future relationships. Development in adolescence has been found to be strongly related to romantic relationship quality compared to early and later periods (Kochendofer & Kerns, 2017), which can explain why adolescent factors emerged as stronger predictors when compared to adult factors.
The present study also adds to existing literature by exploring the association between personality and relationships (early and concurrent) on adult romantic relationship status. This study looked specifically at levels of extraversion, conscientiousness, and neuroticism during adolescence and adulthood, interactions with peers, and quality of relationships with parents during adolescence and adulthood and their association with the presence or absence of a romantic relationship in adulthood.
Results found that higher levels of relationship quality with mothers during adolescence were associated with a greater likelihood of being in a romantic relationship during adulthood. In line with the findings regarding relationship quality, higher levels of extraversion during adulthood were associated with a decreased likelihood of being in romantic relationship in adulthood. This could be related to extraverts wanting to be more social and not having the desire to be in a committed relationship. Existing literature mainly looks at opinions and beliefs towards romantic relationships as predictors of relationship status (Heinze et al., 2020;Arocho et al., 2020;Moore et al., 2012).
When demographics between individuals currently in a relationship and those who were not were compared, several significant differences emerged. Males, Whites, participants and parents with at least some college educational experience, and participants with an average yearly income of less than $29,999 were significantly more likely to be in a relationship. A few of these findings were expected, such as gender, since females tend to have more negative beliefs towards relationships compared to males (Lee, 2018). Previous literature finds that those with higher education and higher incomes tend to have higher quality romantic relationships (Cronger et al., 2010); however, these studies do not seek to examine the likelihood of being in a romantic relationship. In fact, previous research suggests individuals with higher income tend to have higher levels of distrust, which lessens the likelihood of them engaging in relationships (Filinkova, 2019).
Parents of participants who were in a relationship also reported significantly higher average yearly income levels compared to parents of participants who were not in a relationship, which could be explained through parenting practices within higher income families.

Limitations
Throughout this research study, a few limitations surfaced. One main limitation is that Add Health used self-report measure for all variables. Self-report data is used both Wave I and Wave IV, where adolescent and adult participants reported their relationships with parents and peers, as well as their perception of self. Self-report of perceived relationships and personality tendencies may not be as reliable as an observational study of the participant in their environment (Sacred Heart University Library, 2020).
Independent variables were also measured differently within both waves. For parent-child relationships, Wave I utilized four items to measure quality whereas Wave IV only utilized two items. Also, in Wave I, adolescents were asked to report on different aspect of their relationship with their peers while in Wave IV participants were just asked to report the quantity of peers. Inconsistent measures of variables can lead to issues concerning validity.
Another limitation to this study is the lack of a personality measurement scale. As forementioned, because Add Health did not use a specific measure of personality, only three (extraversion, neuroticism, conscientiousness) of the Big Five personality traits could be extracted and analyzed (Young & Beaujean, 2011). This measure was also developed specifically to measure personality in the Add Health study, and therefore has not been used outside of this dataset. Due to this limitation, this study could not account for the other two personality traits (openness and agreeableness) on romantic relationship quality in adulthood.
This study also considered anyone who was sexually or romantically involved with at least one person at the time of data collection to be "in a relationship." Differences in the number of partners may lead to differences within relationship quality.
Future studies should address this issue by limiting "in a relationship" to one partner in order to ensure reliability within results.
Additionally, the sample size for this study was rather large. As larger sample sizes have the ability to transform small differences into statistically significant differences (Faber & Foncesca, 2014), findings could possibly misdirect researchers and clinicians. This warrants caution when using findings to make treatment decisions. On the other hand, larger sample sizes provide a smaller margin of error, and have the ability to identify outliers that could skew data in a smaller sample.
The last study limitation is the lack of diversity within the sample population. The current study consisted of mainly (65.8%) White participants. A lack of diversity in a sample can lead to ethical and research consequences such as the inability to generalize study results and prevents certain population from experiencing the benefits of research (UCSF CTSI, 2021).

Conclusion
Findings from this study can benefit clinicians who work with parents, couples, and adults. Couple and Family Therapists (CFT) can help parents understand the impact of their relationship with their children during adolescence. Clinicians can work with parents towards better relationships with their children to ensure positive, higher quality relationships for the future. CFT's could also utilize these findings when working with adult couples. If a couple perceives themselves as having a lower quality relationship, clinicians can inquire about adolescent relationships with parents or adult personality tendencies to better understand the situation.
Future research regarding predictors of adult romantic relationship quality would benefit from using more reliable research methods. Using observational methods, such as home-observations during adolescence, could produce more reliable results compared to self-report measures which can often result in bias responses, or responses that participants deem acceptable. Future research should also aim to measure all five personality traits and their impact on adult romantic relationship quality. Future studies should utilize datasets and instruments that contain all five factors in order to accurately measure the relationship between personality and adult outcomes. Findings from this study can be useful when looking at personality styles over time and their association with relationship outcomes, as this study measured personality at two points in time.
Future research should explore personality further to understand how extraversion shifts from a positive correlation during adolescence, to a negative correlation during adulthood. A longitudinal study looking at the development of beliefs and views on relationships over time within individuals would help to explain this finding.
In the future, researchers should continue to follow these individuals into parenthood. Researchers can then compare participant's parenting styles to the parentchild relationship quality. It would also be beneficial to look at unique populations, such as single mothers by choice, and whether the choice of not having a romantic relationship can be related to their children's personality and relationship outcomes. Lastly, a more diverse sample would help to expand the findings from this study. More than half of the sample (69%) identified as White. Although this sample is representative of the U.S. population, it indicates the need for future research to look at predictors of romantic relationship quality across multiple races and ethnicities.