The composition of family networks is also expected to change, with grandparents and great-grandparents living longer, but the number of cousins, nieces and nephews declining, the authors noted.

"Canadian children nowadays have fewer cousins than previous generations," said Rania Tfaily, an associate professor in sociology at Carleton University in Ottawa who studies social demography and contemporary changes in marriage and family formation.

This is a key factor in the cousin decline, said Prof. Yue Qian, an associate professor of sociology at the University of British Columbia whose research focuses on social demography.

For example, she said, research shows that Black single mothers often rely on their extended kin for various types of support; gender and sexual minority adults face much higher levels of parental rejection.

"If our society and culture celebrate and value developing close friendships and communities and building family we choose to a greater extent, we may not need to worry about a cousin decline so much."

Saved 84% of original text.