Thanks Phyllis!

That means a lot Marianthi 🥰

13/ And since I have you here, it's time for some shameless plugging!
I defend my PhD ( :O ) next week, and if you are interested in more of what I got up to over the past few years, you can check out an @nrc.nl here: www.nrc.nl/nieuws/2025/...

12/ You can also read the @newscientist.com article here: www.newscientist.com/article/2503...

11/ Many thanks to the Strategic Research Council, @erc.europa.eu, and @rug.nl's Rosalind Franklin Fellowship for funding and everyone who has helped with the project. In particular, my *super*vising team.

10/ Overall, this "natural experiment" yields new insights into the consequences of human reproductive behavior. This gives a biological explanation for previously inconsistent results and evidence in favour of reproductive costs playing an important role in shaping human lifespans.

9/ These differences then disappeared again after the famine, probably because of the improvements in healthcare and reductions in family size in 20th-century Finland.

8/ Mothers exposed during other life stages did not show these costs. This suggests that environmental conditions can influence whether mothers suffer reduced lifespans when having more children, but it is the conditions experienced while actively raising children that are most important.

7/ …mothers reproducing during the famine had shorter lifespans if they had more children – around half a year per child!

6/ Before the famine, mothers having more children did not have shorter lifespans, showing no support for the trade-off between reproduction and survival. However…

5/ To test this, we leveraged a famine event during our historical data, which span 250 years across thousands of Finns. We examined whether mothers having more children lived shorter lives, comparing across mothers not exposed to the Great Finnish Famine, or exposed during different life stages.

4/ Part of an explanation might be that healthy mothers can have more children without paying for these lifespan costs. For example, previous work suggested that the trade-off becomes more visible in poorer socioeconomic conditions.
...but what about the environment?

3/ It follows that women having more children might live shorter lives. Researchers have been looking at this since the early 20th century(!), but results are inconsistent at best. Some studies do show the tradeoff, but others find no relationship or even a positive association.
So what's going on?

2/ Why we age and why some of us age faster than others are HUGE questions that attract a diversity of researchers. One idea – from evolutionary biology – is that there is a trade-off between reproduction and survival (i.e., the disposable soma hypothesis).