Two of the most common nonhuman animals that interact with humans are domestic dogs (Canis familiaris) and cats (Felis catus). In contrast to dogs, the ability of domestic cats to communicate with humans has not been explored thoroughly. We used a habituation-dishabituation method to investigate whether domestic cats could discriminate human utterances, which consisted of cats’ own names, general nouns, and other cohabiting cats’ names. Cats from ordinary households and from a ‘cat café’ participated in the experiments. Among cats from ordinary households, cats habituated to the serial presentation of four different general nouns or four names of cohabiting cats showed a significant rebound in response to the subsequent presentation of their own names; these cats discriminated their own names from general nouns even when unfamiliar persons uttered them. These results indicate that cats are able to discriminate their own names from other words. There was no difference in discrimination of their own names from general nouns between cats from the cat café and household cats, but café cats did not discriminate their own names from other cohabiting cats’ names. We conclude that cats can discriminate the content of human utterances based on phonemic differences.

This study investigated whether 12 participants with color-vision deficiency had superior visual discrimination of color-camouflaged stimuli shown on a computer screen compared with 12 participants with normal trichromatic vision. Participants were asked to distinguish a circular pattern from other patterns in which textural elements differed from the background in orientation and thickness. In one condition, stimuli were single-colored, green or red; in the other condition, stimuli were color camouflaged with a green and red mosaic overlaid onto the pattern. Color-vision deficient participants selected the correct stimuli in the color-camouflaged condition as quickly as they did in the single-colored condition. However, normal color-vision participants took longer to select the correct choice in the color-camouflaged condition than in the single-colored condition. These results suggest that participants with color-vision deficiency may have a superior visual ability to discriminate the color-camouflaged stimuli.

In humans, support from partners and alloparents is crucial for successful child-rearing and optimal child development. However, the complex relationships among childcare support, children's outcomes and parental characteristics have not been fully examined. We investigate how three sources of partner and alloparental support—partner's childcare participation, support from children's grandparents and support from non-kin—can be associated with child social development. We hypothesize that the associations between childcare support from partners/alloparents and child social development are partly mediated by parental psychological condition and parenting style. To test this, we conducted path analyses on online survey data collected in 2016 from parents of 3- to 5-year-old children in Japan. We found no evidence that childcare support had direct positive effects on child social development. Rather, the benefit of childcare support was mediated by its effects on parental psychological condition and parenting style, which in turn improved children's outcomes. At the same time, we found some evidence that greater availability of childcare support was directly associated with more behavioural difficulties in children. Our findings reveal the complex pathways between childcare support, parental characteristics and children's outcomes in Japan, showing potential mechanisms behind parental and alloparental effects in industrialized populations. This article is part of the theme issue ‘Multidisciplinary perspectives on social support and maternal–child health’.

Like humans, common marmoset monkeys utilize family cooperation for infant care, but the neural mechanisms underlying primate parental behaviors remain largely unknown. We investigated infant care behaviors of captive marmosets in family settings and caregiver-infant dyadic situations. Marmoset caregivers exhibited individual variations in parenting styles, comprised of sensitivity and tolerance toward infants, consistently across infants, social contexts and multiple births. Seeking the neural basis of these parenting styles, we demonstrated that the calcitonin receptor-expressing neurons in the marmoset medial preoptic area (MPOA) were transcriptionally activated during infant care, as in laboratory mice. Further, site-specific neurotoxic lesions of this MPOA subregion, termed the cMPOA, significantly reduced alloparental tolerance and total infant carrying, while sparing general health and other social or nonsocial behaviors. These results suggest that the molecularly-defined neural site cMPOA is responsible for mammalian parenting, thus provide an invaluable model to study the neural basis of parenting styles in primates.

Physical and mental effects stemming from COVID-19 have impacted not only people’s lives but also the lives of their pets, which in recent years are often seen as members of the family. This study aimed to explore the impact of the COVID-19 pandemic in Japan on pets and their owners. Participants reported changes in physical activity and mental health, as well as working conditions and frequency of interaction with pets, before and after behavioural restrictions due to the COVID-19 pandemic. We also asked about their pets’ behaviours using the Feline Behavioural Assessment and Research Questionnaire (Fe-BARQ) and the Canine Behavioural Assessment and Research Questionnaire (C-BARQ). This study showed that most cat and dog owners spent more time at home due to the COVID-19 behavioural restrictions and that the frequency of contact interaction with their pets increased. However, this study showed higher stress-related behaviours (e.g., cats: excessive grooming; dogs: aggression towards owners) among pets whose owners increased contact interaction. Furthermore, owners’ low mental health was correlated with high stress-related behaviours (e.g., touch sensitivity) in pets. The results of this study indicate that the lockdown caused by the COVID-19 pandemic in Japan may have affected not only the lives of owners but also the interaction between owners and their pets, and consequently their pets’ behaviours. Therefore, there is also concern that changes in lifestyle patterns caused by pandemics could form a negative feedback loop between the health status of both owners and their pets.

We aimed to clarify the changes in facial morphology of cats in relation to their interactions with humans. In Study 1, we compared the facial morphology of cats (feral mixed breed, owned domestic mixed breed, and owned domestic purebreds) with that of African wildcats. After collecting 3295 photos, we found that owned domestic cats’ noses were significantly shorter than those of African wildcats and feral mixed breed, and there were no significant differences between the latter two. The eye angles were significantly more gradual in owned domestic purebreds than in the other groups. In Study 2, we examined the correlation between facial morphology and years with the owner, and found that the former is not affected by the latter. This suggests that changes in facial morphology are possibly transgenerational changes. The difference in facial morphology between wildcats and owned cats might be caused by domestication, and that between feral cats and owned cats might be due to feralization. In Study 3, we investigated whether cats’ facial features affect cuteness ratings. We asked human participants to evaluate the cuteness of cats’ face images and found that faces with shorter nose lengths were considered cuter. This suggests that owned domestic cats’ facial morphology is preferred by humans.