I don't know who these "scientists" happen to be, but I'd probably argue with a number of these stats! The average age at which you peak at certain things in life...
Learning a new language - 7 ...this is why rich people hire nannies that speak only in a language other than English to their children ...this one makes sense
Attractiveness and life satisfaction - 23 ...if you're telling me life is downhill after 23 that's just rude! Was my face a little more supple at 23? Yes. But was a satisfied with life...I was living with my parents and drinking my extra cash away. I'd say NO!
Finding a partner for marriage - 26 ...well practically all my friends are married so I'll agree. 32 and still single over here!
Running a marathon - 28... I like this number! When I tell people I've run 4 half marathons they ask when I'll do a full. My response "No thank you I don't want to crap my pants". Well now instead of getting stunned looks from people that don't seem to think 13.1 miles is enough I can just say I'm past my prime for a full!