1. The Grandmother Hypothesis
Effect of menopause on grandparental investment

2. An Evolutionary Puzzle
Virtually all other animals reproduce until they die
Why do women go through menopause?
Is it an evolutionary adaption?
What are the fitness enhancing benefits?

3. The Grandmother Hypothesis
After menopause, women redirect reproductive efforts into existing offspring — and their offspring!
Indirect benefits for women’s reproductive fitness

4. Implications
In order for the grandmother hypothesis to provide a persuasive explanation for menopause, postmenopausal women must
provide resources to their offspring / kin
these recourses are beneficial to kin

5. Previous Research
The presence of post reproductive grandparents is associated with
number of grandchildren
grandchild nutrition

6. Implications
In order for the grandmother hypothesis to provide a persuasive explanation for menopause, postmenopausal women must
provide resources to their offspring / kin
these recourses are beneficial to kin

7. Hypothesis
Postmenopausal grandmothers provide greater levels of resources to their grandchildren (compared to premenopausal)

8. How to examine? We need big datasets which measure Menopause status
Grandchild care
Other related factors (age)
Both pre and post menopausal women

9. Roadmap
In two longitudinal datasets, examine whether menopause predicts grandchild care
Study 1: Health and Retirement Study
Study 2: Australian Longitudinal Study on Women's Health

10. Health and Retirement Study
Approximately 20,000 Americans
Representative sample of US population

11. Participants
All participants were included who matched our inclusion criteria
female
grandparent
between the ages of 30-80
either pre or postmenopausal
provided information about time spent caring for grandchildren

12. Grandchild care
How many hours did you spend caring for grandchildren or great-grandchildren in the past two years?
Pre-menopause N=275
Post-menopause N=7256

13. Results
Postmenopausal grandmothers provided greater levels of grandchild care
Results hold even when controlling for age and a variety of other variables
Does menopause also predict volunteering? No

14. Roadmap
In two longitudinal datasets, examine whether menopause predicts grandchild care
Study 1: Health and Retirement Study
Study 2: Australian Longitudinal Study on Women's Health

15. Australian Longitudinal Study on Women's Health
About 18,000 women
years old

16. Participants
All participants were included who matched our inclusion criteria
female (all)
grandparent (not asked)
between the ages of (all)
either pre or postmenopausal
provided information about time spent caring for grandchildren

17. Grandchild care
Do you regularly provide unpaid care for grandchildren or other people’s children?
Premenopause N=3820
Postmenopause N=21245

18. Results
Postmenopausal grandmothers provided greater levels of grandchild care
Results hold even when controlling for age and a variety of other variables

19. Subset of women followed from pre to post menopause; N = 2048

20. Results
Postmenopausal grandmothers do not engage in greater levels of volunteer work
Holds when controlling for age and a variety of other variables

21. Subset of women followed from pre to post menopause; N = 744

22. Summary
Across two longitudinal datasets, menopause status appears to be linked to non-parental child care
Not to volunteering
Take home message: post menopausal women help with care for grandchildren more than premenopausal ones

23. Future Questions How do these effects generalize to other resources?
Money
How do these effects generalize to other kin?
Nieces and nephews
Menopause timing
Could the number of dependent kin influence the timing of menopausal onset?