Across all CM dyads, no differences by history of child foster care placement were observed in mother or child SASB cluster codes, sequential patterns, or RSA scores (all ts ns). Within the full sample, neither child age (rs = −.01 to .01) nor sex (rs = .02 to .07) predicted children’s RSA scores. Given the sample stratification by CM status, sociodemographic indicators (maternal education and household income) were included in the hierarchical regressions on CM status, parent– child transactions, and children’s parasympathetic physiology.
CM differences in parent– child transactions
During the joint challenge task, mothers engaged in a high proportion of SASB Nurture/Protect (i.e., warm guidance) behaviors (M = .56, SD = .17) cluster codes, followed by Strict Control (M = .19, SD = .15), Affirm (i.e., autonomy-support; M = .18, SD = .17), and Hostile Control (M = .03, SD = .06). Next, descriptive statistics for mother and child SASB cluster and sequential codes by physical abuse, neglect, and non-CM groups are shown in . T tests were conducted to assess differences in mother and child cluster codes, and mother– child Lag 1 transitional probabilities by CM status, and then probed for CM subtype differences. As shown in , physically abusive and neglecting mothers displayed more strict Controlling behavior than did non-CM mothers (ps < .006). Physically abusive mothers also engaged in fewer Affirming Autonomy behaviors than non-CM mothers (p = .03). Though mother Nurture/Protect behavior was the most prevalent behavior across groups, accounting for roughly one half of mothers’ speaking turns (i.e., 53% of neglecting to 59% of non-CM mothers’ behaviors), this maternal behavior did not distinguish between CM subtypes nor did it predict children’s RSA scores or successful task completion. In terms of children’s observed behaviors, physically abused children engaged in more Sulking (i.e., hostile submission), relative to neglected (p = .009) and non-CM children (p = .001). Neglected children showed the lowest levels of Autonomous behavior, relative to physically abused children.
Descriptive Statistics for SASB Mother and Child Codes by CM Subtype
Differences were also observed by CM status in the Lag 1 probabilities of positive contingent responding (i.e., mother Affirm–child Autonomy), t(74) = 2.31, p = .02; aversive nonsynchronous responding (i.e., maternal Control conditioned on child Autonomy), t(74) = −2.18, p = .03; and negative contingent responding (i.e., mother Control–child Submit), t(74) = −2.00, p = .05. Mother–child dyads in the physical abuse group engaged in more nonsynchronous (p = .02) and negative contingent (p = .04) transactions, and fewer positive contingent transactions (p = .02) during the joint challenge task, as compared to non-CM dyads, with neglect dyads falling roughly in between the two.
Mother and child physiology patterns by CM subtype
Two CM group (Physical Abuse vs. Neglect vs. Non-CM) × task (baseline vs. joint challenge) repeated measures ANOVAs were conducted with child and mother RSA scores entered as the dependent variable. Main effects were observed for children on Task F(1, 59) = 31.73, p < .0001, indicating a significant reduction in children’s RSA scores from baseline to the joint challenge task. Analyses conducted on mothers’ RSA scores also revealed significant Task effects, F(1, 58) = 10.78, p = .002, demonstrating RSA increases from baseline to joint challenge task (see ). Neither CM subtype main effects nor CM × Task interactions were significant for children or mothers in terms of predicting the slope of RSA changes.
Child and mother RSA values during resting baseline and joint challenge task by CM subtype. Note. RSA values in milliseconds square (msec2).
To represent the mother– child differences in RSA change, we defined vagal suppression as RSAΔ scores >0, and RSAΔ scores >0 as indicating vagal augmentation.
Inspection of individual differences in children’s RSAΔ scores showed that 75.9% children displayed vagal suppression from baseline to the joint task, while 24.1% of children showed vagal augmentation. In contrast, most mothers’ RSAΔ scores revealed a pattern of vagal augmentation (70.4%) while interacting with their child, while the remaining (29.6%) demonstrated vagal suppression. Rates of suppression and augmentation significantly differed between mothers and children (McNemar’s exact test p = .001), though no CM group differences emerged for direction of children or mothers’ individual change scores. Exam of dyadic patterns of RSAΔ indicated over half of the dyads (51.9%) engaged in a mother RSA augmenting– child RSA suppressing pattern from resting baseline to the joint challenge task. Only three dyads (5.6%) showed the opposite pattern (i.e., mother RSA suppression– children RSA augmentation), all of whom were in the CM-Neglect group.
CM, Parenting Processes, and Children’s Physiology
To test the incremental prediction of CM status and mother– child Lag 1 transitions on children’s parasympathetic regulation, hierarchical regression models were fit to the data. Given the sample stratification, sociodemographic indicators (income and maternal education) were included as covariates. As shown in , three models were examined each for children’s task RSA and RSAΔ: (a) positive contingent responding, that is, maternal Affirm given child Autonomy [P(1–2 | 2–1 & 2–2)]; (b) aversive nonsynchrony, that is, maternal Control given child Autonomy [P(1–5 & 1– 6 | 2–1 & 2–2)]; and (c) negative contingent responding, that is, maternal Control given child Submit/Sulk [P(1–5 & 1– 6 | 2–5 & 2– 6)]. Dependent variables were children’s joint task RSA or children’s RSAΔ (i.e., baseline to task) and covariates identified above were included in the models. Baseline RSA scores were also covaried in the models predicting child RSAΔ.
Hierarchical Regressions Testing the Effects of CM Status and Mother–Child Autonomy–Control Sequences on Children’s Vagal Tone
Hierarchical regression of children’s joint task RSA scores onto maternal positive contingent responding, controlling for effects of maternal education, income, and CM status, was not significant, ΔF(1, 58) = 1.06, p = .31, ΔR2 = .02. As shown in , step 2 entry of physical abuse and neglect was significant, F(2, 59) = 4.20, p = .02, ΔR2 = .12, indicating that both uniquely predicted lower task RSA. Regression of child RSAΔ scores onto mother’s positive contingent responding was significant, ΔF(1, 54) = 4.78, p = .03, ΔR2 = .06, after covarying education, income, CM status, and children’s baseline RSA scores. Interpretation of regression coefficients showed that mother affirming– child friendly autonomy transitions predicted less RSA suppression (i.e., higher parasympathetic tone) while the child was engaged in the moderately challenging task with mother, relative to children whose mothers were less affirming of their autonomous behavior. Baseline RSA scores and maternal education also uniquely predicted children’s RSAΔ scores.
Regression of child task RSA scores onto mother aversive nonsynchronous responding was also significant, ΔF(1, 58) = 8.14, p = .006, ΔR2 = .10. Children who experienced higher proportions of maternal controlling & criticizing in response to their friendly autonomous behavior showed lower task RSA and greater RSA suppression. Physical abuse and maternal education also significantly predicted task RSA scores. Nonsynchronous responding also emerged as a significant unique predictor of children’s RSAΔ scores, ΔF(1, 55) = 4.60, p = .04, ΔR2 = .07. However, aversive contingent responding (maternal control/criticize– child submit/sulk) was neither a significant predictor of children’s task RSA, ΔF(1, 58) = .96, p = .33, nor RSAΔ scores, ΔF(1, 55) = .20, p = .65.
Follow-up tests were conducted to determine whether positive contingent responding and aversive nonsynchrony would each continue to predict children’s RSA scores, after controlling for base rates of mother Affirm or Control/Criticize codes. After covarying base rates of SASB Affirming (along with SES, CM status, & baseline RSA), the effects of positive contingent responding on children’s RSAΔ scores were attenuated to the null, ΔF(1, 54) = 2.03, p = .16. Conversely, after partialing out base rates of SASB Control/Criticize, the effects of mother– child aversive non-synchrony (control child autonomy) on children’s task RSA and RSAΔ scores remained significant, ΔF(1, 55) = 4.49, p = .04, ΔR2 = .06, and ΔF(1, 53) = 9.68, p = .003, ΔR2 = .10, respectively. Mean levels of maternal Control varied by CM status, but the negative effects of Control on child parasympathetic tone were only observed when it immediately followed children’s friendly autonomous bids. In contrast, higher mean levels of maternal Affirming Autonomy predicted higher RSA, regardless of children’s antecedent responses. Finally, two sets of three hierarchical multiple regressions were conducted to examine whether CM status moderated relations between parenting transactions and children’s parasympathetic physiology, however, no significant interactions were observed.