A new study that is based on a database of 3 million mobile phone subscribers suggests that women are more inclined to ‘invest heavily in creating and maintain a pair-bond’ than men.

The study also suggests that women also are more likely to switch ‘preference ranking’ which makes them more focused. They pay attention to individuals in their lives and it varies according to the passage of time, from spouses to children to grand-children. In men, relationships are more diffuse and men call their spouses more often during the initial seven years of the relationship after which they shift focus to other friends.

The study included 1.95 billion phone calls and 489 million text messages and was based on the assumption that more number of calls or texts to a person tend to show the closeness of the relationship.

According to the study, pair bonding and investing in relationships is more important to women than it is to men “It’s the first really strong evidence that romantic relationships are driven by women,” said Professor Robin Dunbar of Oxford University.

Women, the researchers say, tend to shift attention from their spouse to their daughters as they grow older. It is women who shift alliances more often and show greater gender-biases.

“What seems to happen is that women push the ‘old man’ out to become their second best friend, and he gets called much less often and all her attention is focused on her daughters just at the point at which you are likely to see grandchildren arriving,” Dunbar told BBC.

Human society is often believed to be based on male-male relationship whereas the study provides evidence that it is the mother-daughter relationship that plays an important role in structuring the society.

“Men’s relationships are too casual. They often function at a high level in a political sense, of course, but at the end of the day, the structure of the society is driven by women, which is exactly what we see in the primates,” said Dunbar.

The research data came from a large scale database from a single mobile service provider in a European country.

“If you look at the hunter gatherers, and you look at modern humans in modern post-industrial societies, we are much more matriarchal. It’s almost as if the pendulum between the two sexes, power-wise, is swinging (back) as we move away from agriculture towards a knowledge-based economy,” Dunbar said in his argument against human society being a patriarchal society.

The study is published in the journal Science Reports.