Links between pubertal timing and tempo and the timing and tempo of other-sex friendships

• In Event: Friendships and Peer Relationships in Adolescence

Abstract

Theory asserts that adolescents with earlier puberal timing initiate other-sex friendships earlier than their on-time and late counterparts (Magnusson et al, 1986). Although limited, empirical evidence shows that individuals with earlier pubertal timing experience earlier timing of establishing other-sex friendships (Bucci et al., 2021) and steeper tempo of other-sex friendship uptake (Poulin & Pedersen, 2007). Also, females initiate other-sex friendships earlier than males (Poulin & Pedersen, 2007). It is yet unknown whether pubertal tempo is associated with the timing and tempo of other-sex friendship uptake. We add to this literature by examining sex differences in the timing and tempo of other-sex friendship uptake and the association between the timing and tempo of puberty and the timing and tempo of other-sex friendships.

Participants were 1020 adolescents from a cohort longitudinal study (Jackson et al., 2021), aged 10-15 years (M=12.22, SD=0.98) and were White non-Hispanic (72%), Black non-Hispanic (4%), and Hispanic (12%), with 33% receiving subsidized/free lunch at baseline. Adolescents reported their pubertal development using the Pubertal Development Scale (Petersen et al., 1988) as well as the sex of their three closest friends at six timepoints over a three-year period. We used established pubertal timing and tempo scores estimated using nonlinear growth curves (Marceau et al., 2015). Other-sex friends timing and tempo scores (the effect of age, centered at 13-years) were estimated using generalized linear mixed models (SAS PROC GLIMMIX; using laplace estimation and multinomial outcome distribution; see Table 1). Empirical estimates for individual timing and tempo scores for both phenotypes were extracted from the models and used for hypothesis testing.

Independent t-tests were run to test the hypothesis that there are sex differences in the timing and tempo of other-sex friendship uptake. To test the hypothesis that pubertal timing and tempo are associated with the timing and tempo of other-sex friendship uptake, we used path analysis conducted in R(lavaan; using FIML and bootstrapped standard errors; Rosseel, 2012) separately by sex, consistent with the broader literature on puberty. Covariates included: grade at baseline, cohort, average friendship stability (same friends reported at multiple waves), and average proportion of older and younger friends (defined as +/-1 year).

Intraclass correlation from the unconditional model indicated that 42% (ICC=0.418) of the variance in proportion of other-sex friends was between-individual. Proportion of other-sex friends increased with age (Table 1, a_fixed), and there were individual differences in the linear change (Table 1, a_random). Independent t-tests showed that females had earlier timing of other-sex friendships, t(1018)=-2.14, p<0.05, but not other-sex friendship tempo, t(1018)=0.22, p=0.82. Path analyses results (Figure 1) showed that earlier pubertal timing was related to the later timing of other-sex friendship uptake (r = -0.20, p < 0.05) only for males. There were no other associations of pubertal timing and tempo with opposite-sex friend timing or tempo for males or females. Thus, pubertal development appears to be unrelated to the development of other-sex friendships for females but males who enter puberty earlier remain in majority same-sex friendship contexts longer than their on-time and late maturing counterparts.

Authors

• Amy Milin Loviska, Purdue University, West Lafayette
  Presenting Author

• Kristine Marceau, Purdue University, West Lafayette

• Valerie Knopik, Purdue University, West Lafayette

• Michelle L Rogers, Brown University School of Public Health

• Kristina Jackson, Brown University