London - Mothers unhappy with their male partners spend more time talking to their first child than those in happy relationships.
But the finding applies only if it is a boy, according to a study, as moms in unhappy marriages did not speak more to girls.
The study was based on recordings of conversations between parents and their babies. Researchers also found moms were much more chatty than dads when looking after their baby.
The research is significant as exposure to speech is thought to help a child develop language ability. However, the researchers from Cambridge University said it was too early to say if being exposed to more speech improved language skills. The study involved 93 first-time heterosexual parents and their interactions with their child.
The parents wore a device which recorded talk during the day. They also filled in questionnaires about the state of their relationship.
In the research published in the Journal of Family Psychology, the more dissatisfied a couple were with their relationship, the more the mother spoke to her son but not her daughter. Mothers who reported the quality of their relationship to be "low" used around 35 percent more words to her son than a mother whose relationship was "average" and started around 20 percent more conversations.
The content of the talk was not analysed so it is not clear if the mother was complaining to her infant or talking positively.
Dr Elian Fink from the Centre for Family Research said: "It’s possible that the mum is trying to compensate for the poor relationship she has with her partner by putting more time and effort into her relationship with her other close male social partner, her son.
"Mums only seem to compensate when they have infant sons, not daughters. It could be that mothers view their daughters as mini-versions of themselves rather than of their partners."
The authors said fathers showed "significantly less overall talk" and started fewer conversations. The amount a father spoke to their child was unrelated to the quality of the couple’s relationship.
Dr Fink added: "Even when dads spend more time around their infants, this doesn’t necessarily mean they are interacting more. One possible reason may be that there’s still an imbalance in who responds to the basic care needs of their infant."