In their research paper – Genetic variation in offspring indirectly influences the quality of maternal behaviour in mice– Ashbrook et al. show that if a mother is already a generous provider, she will be nagged less by her offspring.
The study in mice uncovers a fitness cost to begging for care, so pups don’t continue asking for more if they are already well provided. Pups that spend more time soliciting for care weigh less than those that are more easily satisfied. These findings are applicable to any social species, including humans.
The level of maternal care was measured as the sum of nursing, suckling and nest-building behaviour. A key part of the study looked at how genes expressed in offspring influence their mother’s behaviour.
“For the first time we have identified specific genetic variations in offspring that lead to preferential maternal treatment, which in turn improves offspring fitness. There will therefore be a strong selection pressure on genes expressed in offspring that influence parental behaviour,” says first author David Ashbrook, a PhD student from Manchester.
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