Scientists from the USA: grandmothers are more emotionally attached to their grandchildren than to their children 
in grandmothers, areas of the brain associated with emotional empathy are activated, and in children, areas associated with cognitive empathy. According to experts, this indicates a greater emotional attachment to the former. An article by scientists that reveals the mechanism of the work of the brain of grandmothers was published in the journal Proceedings of the Royal Society B.
Homo sapiens is characterized by cooperative reproduction, in which mothers receive assistance in caring for their offspring. According to the so-called “grandmother hypothesis,” women arose menopause to create evolutionary benefits for their children, who could have more offspring, and grandchildren, who could receive more food – as evidenced by the study of traditional societies. Societal evidence also suggests that grandmothers' parenting participation is associated with improved academic performance, behavior and children's physical health.
The experiment by researchers from Emory University involved 50 grandmothers with at least one grandchild or one granddaughter between the ages of three and 12 years. To begin with, they were asked to fill out questionnaires about their experiences – how much time they spend with their grandchildren and what they do. After that, specialists using functional magnetic resonance imaging studied the brain activity of the participants while they looked at photographs of their grandchildren and granddaughters, their mothers, as well as unknown children and adults.
It turned out that the greatest activity during the observation of grandchildren was observed in areas of the brain associated with emotional empathy – the ability to experience the same feelings and emotions as another person. At the same time, when the participants looked at photographs of their daughters, they activated more areas of the brain associated with cognitive empathy – the ability to understand the point of view of another person. This suggests, the researchers note, that they seek to understand what their children think and feel, but they do not evoke the same emotional response as grandchildren. The grandmothers with the greatest activation of these areas noted in the questionnaires that they would like to have more participation in the lives of their grandchildren and granddaughters.
Comparison with the results of a similar study conducted by the researchers for fathers earlier showed that grandmothers, on average, have more activated brain regions associated with emotional empathy and motivation. “Our findings provide further evidence of a shared parenting system in the brain,” said lead author, Emory University professor James Rilling.