The predictive validity of the strange situation procedure: Evidence from registered analyses of two landmark longitudinal studies.

Meta-analyses demonstrate that the quality of early attachment is modestly associated with peer social competence (r = .19) and externalizing behavior (r = -.15), but weakly associated with internalizing symptoms (r = -.07) across early development (Groh et al., Child Development Perspectives, 11(1), 70-76, 2017). Nonetheless, these reviews suffer from limitations that undermine confidence in reported estimates, including evidence for publication bias and the lack of comprehensive assessments of outcome measures from longitudinal studies in the literature. Moreover, theoretical claims regarding the specificity of the predictive significance of early attachment variation for socioemotional versus academic outcomes had not been evaluated when the analyses for this report were registered (but see Dagan et al., Child Development, 1-20, 2023; Deneault et al., Developmental Review, 70, 101093, 2023). To address these limitations, we conducted a set of registered analyses to evaluate the predictive validity of infant attachment in two landmark studies of the Strange Situation: the Minnesota Longitudinal Study of Risk and Adaptation (MLSRA) and the NICHD Study of Early Child Care and Youth Development (SECCYD). Across-time composite assessments reflecting teacher report, mother report, and self-reports of each outcome measure were created. Bivariate associations between infant attachment security and socioemotional outcomes in the MLSRA were comparable to, or slightly weaker than, those reported in the recent meta-analyses, whereas those in the SECCYD were weaker for these outcomes. Controlling for four demographic covariates, partial correlation coefficients between infant attachment and all socioemotional outcomes were r ≤ .10 to .15 in both samples. Compositing Strange Situations at ages 12 and 18 months did not substantively alter the predictive validity of the measure in the MLSRA, though a composite measure of three different early attachment measures in the SECCYD did increase predictive validity coefficients. Associations between infant attachment security and academic skills were unexpectedly comparable to (SECCYD) or larger than (MLSRA) those observed with respect to socioemotional outcomes.

Mice lacking membrane estrogen receptor 1 are protected from reproductive pathologies resulting from developmental estrogen exposure†.

Both membrane and nuclear fractions of estrogen receptor 1 (ESR1) mediate 17ß-estradiol (E2) actions. Mice expressing nuclear (n)ESR1 but lacking membrane (m)ESR1 (nuclear-only estrogen receptor 1 [NOER] mice) show reduced E2 responsivity and reproductive abnormalities culminating in adult male and female infertility. Using this model, we investigated whether reproductive pathologies caused by the synthetic estrogen diethylstilbestrol (DES) are mitigated by mESR1 ablation. Homozygous and heterozygous wild-type (WT and HET, respectively) and NOER male and female mice were subcutaneously injected with DES (1 mg/kg body weight [BW]) or vehicle daily from postnatal day (PND) 1-5. Uterine histology was assessed in select DES-treated females at PND 5, whereas others were ovariectomized at PND 60 and treated with E2 (10 µg/kg BW) or vehicle 2 weeks later. Neonatal DES exposure resulted in ovary-independent epithelial proliferation in the vagina and uterus of WT but not NOER females. Neonatal DES treatment also induced ovary-independent adult expression of classical E2-induced transcripts (e.g., lactoferrin [Ltf] and enhancer of zeste homolog 2 [Ezh2]) in WT but not NOER mice. At PND 90, DES-treated WT and HET males showed smaller testes and a high incidence of bacterial pyogranulomatous inflammation encompassing the testes, epididymis and occasionally the ductus deferens with spread to lumbar lymph nodes; such changes were largely absent in NOER males. Results indicate that male and female NOER mice are protected from deleterious effects of neonatal DES, and thus mESR1 signaling is required for adult manifestation of DES-induced reproductive pathologies in both sexes.

Multigenerational effects of bisphenol A or ethinyl estradiol exposure on F2 California mice (Peromyscus californicus) pup vocalizations.

Rodent pups use vocalizations to communicate with one or both parents in biparental species, such as California mice (Peromyscus californicus). Previous studies have shown California mice developmentally exposed to endocrine disrupting chemicals, bisphenol A (BPA) or ethinyl estradiol (EE), demonstrate later compromised parental behaviors. Reductions in F1 parental behaviors might also be due to decreased emissions of F2 pup vocalizations. Thus, vocalizations of F2 male and female California mice pups born to F1 parents developmentally exposed to BPA, EE, or controls were examined. Postnatal days (PND) 2-4 were considered early postnatal period, PND 7 and 14 were defined as mid-postnatal period, and PND 21 and 28 were classified as late postnatal period. EE pups showed increased latency to emit the first syllable compared to controls. BPA female pups had decreased syllable duration compared to control and EE female pups during the early postnatal period but enhanced responses compared to controls at late postnatal period; whereas, male BPA and EE pups showed greater syllable duration compared to controls during early postnatal period. In mid-postnatal period, F2 BPA and EE pups emitted greater number of phrases than F2 control pups. Results indicate aspects of vocalizations were disrupted in F2 pups born to F1 parents developmentally exposed to BPA or EE, but their responses were not always identical, suggesting BPA might not activate estrogen receptors to the same extent as EE. Changes in vocalization patterns by F2 pups may be due to multigenerational exposure to BPA or EE and/or reduced parental care received.