Assessment of parental bonding in single- versus two-parent mouse pups

A secure attachment relationship in childhood is closely related to the development of an individual. Attachment to the father especially predicts children’s exploratory behavior. It is of importance to gain more insight into the role of father’s attachment in the cognitive development of the offspring. Experimental studies with laboratory mice are theoretically and practically feasible alternatives to study the attachment relationship and its outcomes in a more controlled manner. In this study, we aimed to investigate the social preference and exploratory tendency of C57BL/6 laboratory mice, and the effects of cohabitant father, mother sensitivity and age on social preference and exploratory tendency.

Three main research questions were formulated: (1) Do pups show a preference to the mother or the father in case they have a cohabitant father? (2) Do pups show a preference to the mother or to the outside cohabitant father in case they are tested with an outside cohabitant father? (3) Do pups show a preference to their own father or the outside cohabitant father in case they have a non-cohabitant father? In the meantime, the research questions also incorporated the effect of father cohabitation, mother sensitivity and age of the pups on the social preference and exploratory tendency of the pups. Three testing conditions were designed: mother vs. father, mother vs. other father and father vs. other father, to cover all planned comparisons. The social preference data was collected with the assistance of ANY-maze video tracking system.

The statistical results showed that pups preferred mother to father and outside cohabitant father, and pups in general showed equal preference to the father and the comparison father. However, pups with own non-cohabitant father preferred the outside cohabitant father to their own father. Father cohabitation effect was found to be significant in affecting the social preference and the exploratory tendency of the pups in all three conditions. Age was found significant in predicting the exploratory tendency of the pups in all three conditions, and sensitivity was found significantly predicting the exploratory tendency in mother vs. father condition and social preference significant in mother vs. other father condition.

Our results suggest that father cohabitation has a positive effect on the social preference of the pups to the father and the exploratory tendency of the pups. The study can be used as a prototype to study father attachment in laboratory mice.