Over the past couple centuries, declining mortality rates have made it possible for people to spend more years of their lives as sons or daughters, spouses, parents, and grandparents. Yet concurrent changes in marriage, divorce, and fertility patterns mean we’re spending smaller proportions of our lives in some of these roles. We spend a smaller fraction of our lifespan as spouses and parents of young children now than people did in the year 1800, for instance.

What about as grandparents? Falling mortality rates and delayed fertility push in opposite directions in this case. Today’s older adults tended to have children later in life than their parents did (if at all), and their grown children are putting off parenthood even more. On the other hand, adults can also expect to live longer, which might offset the effects of delayed parenthood on the time they will spend as grandparents.

Sociologist Rachel Margolis investigates how these changes have recently played out in Canada in an article for the Journal of Marriage and Family. The family lives of Canadians and Americans have not evolved in identical ways, but are similar enough for her findings to have relevance here. The years she compared, with data from the Canadian General Social Survey and Canadian life tables, were 1985 and 2011. Trends in declining mortality and delayed fertility were already well underway by 1985, of course, and continued in the following years.

Margolis found that although fertility trends have resulted in people becoming grandparents at older ages, they were just as likely to (eventually) become grandparents in 2011 as in 1985. In the 1985, almost six in ten Canadian women in their early fifties were grandmothers; in 2011, less than three in ten. For men in their early fifties, the figures were 44 percent and 22 percent.

Despite first seeing the birth of a grandchild at older ages, women of 2011 could expect to spend a similar amount of time as grandmothers as their 1985 counterparts. Margolis estimated that a 20-year-old woman in 1985 could expect to be a grandparent for 24.7 years, versus 24.3 years for a 20-year-old of 2011 (a statistically insignificant difference). Women’s increase in life expectancy meant that the proportion of life spent as a grandmother declined a bit.

The story was a bit different for men. Men, too, are becoming grandparents at older ages—even older ages than women. Yet men’s larger increase in life expectancy (about six years at age 20, compared with around 3.5 years for women of the same age) outweighed the effect of this trend, such that a 20-year-old man in 1985 would spend 17.0 years of life as a grandparent, whereas his 2011 counterpart would enjoy 18.9 years. Even proportionally, that means a slightly longer period of grandparenthood.

Might becoming a grandparent at a later age affect how much people can actually do with their growing grandkids? The concern is not unfounded, but in Canada, at least, grandparents were healthier in 2011 than in 1985, despite being older on average. And if people spend more years of grandparenthood as retirees, they could potentially be more involved with their grandkids. Although acting as a primary caregiver to grandchildren may have mixed effects on individuals’ health, Margolis writes that “grandparenthood is reported to be one of the most satisfying parts of older age.” I can’t promise that these findings will turn impatient parents into grandparents any sooner, but young adults, take note: seeing your parents play with your kid is highly satisfying, too.