Optimal responsiveness to infant cues, an integral component of parental caregiving, is thought to be determined by multiple factors including maternal mood, previous experiences of caregiving, and infant characteristics. This thesis builds on previous work and details novel investigations of brain, affective, and attitudinal responses to infants/children. In the first two studies, we investigated the effects of maternal mood and parity (previous experiences of caregiving) on brain response to affectively positive infant pictures using functional magnetic resonance imaging (fMRI). We found that mothers with postpartum depression showed an elevated right amygdala response to infant pictures in comparison to mothers without PPD and depressed non- mothers. Further, functional connectivity between the bilateral amygdalae and the right insular cortex was negatively correlated with clinical symptoms (self-reported depression and anxiety). Therefore, as depression and anxiety symptoms increased amygdala to insular cortex connectivity decreases and vice versa. In the third study, we developed a novel data-driven infant cuteness (DDIcute) metric using the infant pictures presented in the first two studies. In line with ethological postulations on cuteness (infant characteristics), we found that infant pictures with a higher DDIcute score were associated with increased positive/approach-related affective responses and decreased negative/avoidant-related affective responses. In the fourth study, we investigated whether the sex differences in attitudes about children and childcare were moderated by pet ownership/care (previous experiences of caregiving). We found that pet ownership and care eliminated sex differences in attitudes about children and childcare. This effect was driven by males; compared to males with low levels of experience caring for pets, males with high levels of experience caring for pets had more positive attitudes about children and childcare. / Thesis / Doctor of Science (PhD) / The work presented in this thesis adds to literature on human caregiving. In different studies we investigated brain, emotional, and attitudinal responses to human babies and children in people with and without depression as well as in people with different levels of caregiving experience. In the first two studies, we measured brain response to smiling baby pictures in depressed and non-depressed mothers and non-mothers. The amygdala is a brain region that is involved in the neurobiology underlying both depression and maternal behaviour. We found that amygdala response was the highest among mothers with postpartum depression. We also found that the coupled activity of the left and right amygdalae and another brain region called the insula was altered in mothers with postpartum depression. In the third study, we measured facial features of the baby faces presented in the first two studies to develop a measure of cuteness. We also measured emotional responses to the baby faces. We found that cuter infants elicited more positive and less negative emotional responses. In the fourth study, we measured differences in attitudes about children and caregiving between men and women who did and did not own and care for pets—specifically dogs and/or cats. We found that compared to men who did not own and/or care for pets, men who had more experience caring for pets had more positive attitudes about children and childcare.