Table 4.

Linear mixed model for females’ friendships and plasma vasopressin concentrations.

Variable	B	Standard error
Birth cohort: 2002	161.17*	70.86
Birth cohort: 2003a	–	–
High Rank	−55.76	88.75
Middle Ranka	–	–
Low Rank	−41.11	66.48
Total Friendships	37.07b	18.13
Play Friendships	−63.44 b	31.64

^aReference category; ^b0.05 < p < 0.10; *p < 0.05.