Traut · Journal of personality and social psychology 2025 · prospective longitudinal dyadic cohort study · n=1,036 couples (2,072 individuals)

Examining change in attachment in romantic couples: The role of relationship characteristics and codevelopment between partners.

Level 3 - non-randomized controlled study

Prospective longitudinal dyadic cohort study

PubMed 40272431 · doi:10.1037/pspp0000558 · record verified 2026-08-26

What was done

Dyadic growth curve modeling of a prospective longitudinal cohort of 1,036 established romantic couples (mean age 32.9 years, mean relationship duration 8.6 years) followed over 20 months. The study assessed trajectories of attachment anxiety and avoidance, evaluated codevelopment between partners, and analyzed actor and partner effects of baseline relationship characteristics (satisfaction, commitment, support, closeness, responsiveness, and disclosure).

What was found

The abstract reports no numerical effect sizes or test statistics. Dyadic growth models revealed small but significant decreases in attachment anxiety over time exclusively in women, which were negatively associated with relationship duration. Attachment avoidance remained stable over 20 months. No attachment codevelopment between partners was detected. Attachment changes were largely independent of baseline relationship characteristics, though women with highly committed and responsive partners exhibited weaker declines in anxiety.

Why it matters

These findings suggest that adult attachment avoidance is remarkably stable in established relationships and that modest reductions in anxiety occur primarily in women without strong influence from partner dynamics or codevelopment.

Limits

The abstract provides no exact numerical estimates, test statistics, or confidence intervals. The sample was limited to established couples (mean relationship length 8.6 years), which may not generalize to early-stage relationships. The 20-month follow-up may be too brief to detect slower attachment shifts, and reliance on self-report measures introduces potential reporting bias.