Postnatal maternal mood provides evidence for the psychic pain hypothesis; mothers’ depressive mood was sensitive to subtle signs of lower infant health

Kardum, I., Hudek-Knezevic, J., Kalebić Maglica, B., & Shackelford, T. K. (2022). Postnatal maternal mood provides evidence for the psychic pain hypothesis. Evolutionary Behavioral Sciences, 16(2), 116–127. https://doi.org/10.1037/ebs0000256

Abstract: We tested predictions derived from the psychic pain hypothesis according to which depressive symptoms after delivery signal to a mother that she is suffering or has suffered a fitness loss. The predictions were tested on a range of mild emotional states, that is, moods, which allowed us to assess whether the consequences of unfavorable maternal conditions are limited to depressive mood or include other negative and positive moods. In a longitudinal study of 150 women, we measured positive and negative moods twice: during the last trimester of pregnancy and 1–3 months after delivery. As an index of infant quality, we used the mean of Apgar scores measured at 1 and 5 min after delivery, and as an index of maternal circumstances, we used perceived family social support. Supporting the psychic pain hypothesis, after controlling for mothers’ moods before delivery, Apgar score and perceived family social support as well as their interaction predicted mothers’ negative moods after delivery, especially depressive mood and rejection. Additionally, mothers’ depressive mood was sensitive to subtle signs of lower infant health. Perceived family social support and Apgar score were weaker predictors of mothers’ positive moods after delivery. Theoretical and practical implication of these results are discussed.