A new study finds that the more a woman self-identifies with her profession, the more paid hours she works and the less time she spends with the couple's children, but the more equal the childcare balance is between a couple.
However, the more a woman identifies herself with motherhood, the less time the father spends with the children.
And while the more a man self-identifies as a parent the more time he spends with children, this had no impact on the amount of time the woman spends on childcare - regardless of her self-identity.
The study, from Cambridge University's Department of Sociology, extensively surveyed 148 couples with at least one child aged 6 years or younger to explore how both self-aware and - to some extent - latent individual priorities and ideologies help shape decisions about parenting.
Published recently in the journal Psychology of Women Quarterly, researchers say this is one of the first major studies to analyse how parental and work identities of both fathers and mothers impact on childcare.
They call for a thorough examination of the complex ways in which identities guide childcare choices far beyond traditional social structure - of which this study is just the start.
"Full-time employment is still the default option for men; new mothers are expected to remain available to care for their children," said Dr Ruth Gaunt, now at Lincoln University's School of Psychology, who led the study.
"Women need to overcome internal and external barriers to commit to full-time employment, and our findings help reveal the ways in which their internalised identities guide their decisions."
Motherhood and fatherhood are 'socially loaded' terms, say researchers, and direct questioning may skew answers due to societal expectations. So, in addition to testing the importance people consciously attach to their identities, the researchers used an indirect technique to measure what's known as 'identity salience': an individual's latent, underlying hierarchy of identity across various situations.
A series of "Who am I?"-style statements prompted participants to try and define themselves in terms of relationships and roles such as being a son, sister, spouse and so on. While this provoked mention of a vast range of identities, the researchers only noted those that were parental and work-related.
They then ranked these by how quickly each one was raised to get a sense of priority e.g. a score of 10 meant the identity was mentioned first, a 9 for getting mentioned second, and so on; allowing scientists to delve past the self-consciousness of participants.
The researchers analysed both self-conscious identity and the more latent 'identity salience' in the couples separately, as well as separating men and women during questioning.
They found that, in both identity measures, the more a woman identified as a 'mother', the greater her share of childcare tasks relative to the father; the more hours she was sole carer of the child; the greater the gap between mother's and father's hours of care. The women in the sample who identified most with their maternal role tended to do all childcare tasks - such as changing, bathing, playing - by themselves.
The more important a woman's work identity, the smaller her share of childcare tasks relative to the father, and the fewer hours she was sole care provider for the child. Importantly, this meant the gap between hours of care provided by men and women was smallest in couples where women had strongest professional identities.
Essentially, the more a woman self-identified with her profession, the more equal the balance of childcare in a couple.
In contrast, strong paternal or work-related identity only related to the father's own hours of childcare, and had no effect on the amount of childcare time and duties taken on by the mother.
"We assume that women who place more importance on maternal identities have a greater need to validate their identity, and maintaining main responsibility for childcare serves this need - resulting in lower involvement of fathers. Our pattern of results is most consistent with this interpretation," said Gaunt.
While, as with many countries, women's employment rates in the UK have shot up over the last few decades, this country is still dominated by a male-breadwinner/female-caregiver ideology, says Gaunt, with most mothers expected to get part-time work if at all.
"In fact, while the UK has one of the highest general employment rates in Europe for mothers of preschool children, it has one of the lowest rates of maternal full-time employment - with just one in five couples both in full-time work," she said.
"We believe these patterns can partly be explained by the lack of state provision of childcare for small children, combined with social disapproval of full-time employment for mothers."