>> Males were significantly more likely than females to list romantic attraction as a benefit of opposite-sex friendships, and this discrepancy increased as men aged—males on the younger end of the spectrum were four times more likely than females to report romantic attraction as a benefit of opposite-sex friendships, whereas those on the older end of the spectrum were ten times more likely to do the same.
Accordingly, we aimed to compare the
extent to which emerging adults (late adolescence to mid-twenties) and young and
middle-aged adults (late twenties to about 50) experience attraction to their cross-sex
friends
From the linked paper. That's for the follow-up study.
In a follow-up study, 249 adults (many of whom were married) were asked to list the positive and negative aspects of being friends with a specific member of the opposite sex.
There was a follow-up study, but it doesn't say how much, if any, of the original research was tried again.
This is what passes as science in 'scientific american'?! There's not a single absolute number reported aside from the laughingly small sample size of 400 adults in a world of 7,000,000,000.
A random sample of 400 is enough to give a good estimate, regardless of the size of the population.
This is a non-intuitive result from statistics. The standard deviation - the average expected error - does not actually depend on the population size. It could be 7 billion or 7 hundred. The standard deviation only depends on the sample size, and is O(1/sqrt(n)).
In this case, with n=400, we have O(0.05). If we are testing a random variable with two values, then the true deviation is less than 0.5, so the expected error is 0.025 - we expect no more than 2.5% of mistake. That's very good!
(The bigger question is whether the sample is random or not.)
I agree on the bigger question. I thought I was communicating the lack of random samples, but I appreciate you pointing out why just referencing the sample size is not good enough in a sense. Anyways, they practically required lack of randomness. Their sign-up took place at the same school and "requested that participants be traditional college students of heterosexual orientation". Then they obtained the older generation participants by getting the first group to hand over addresses of their older relatives, neighbors and employers. I don't think it could get much less random.
Given the claim in the title they talk about "men and women". So the sample size is small because:
1) zero variance in location
2) very little variance in age (all undergraduate) (variances of the ages: 1.33 to 7.19, so 70% of their samples all were in two age ranges, one 3 year wide, one 14 year wide)
3) cultural variation : essentially zero (?) they didn't even bother to check AFAICT
>> Males were significantly more likely than females to list romantic attraction as a benefit of opposite-sex friendships, and this discrepancy increased as men aged—males on the younger end of the spectrum were four times more likely than females to report romantic attraction as a benefit of opposite-sex friendships, whereas those on the older end of the spectrum were ten times more likely to do the same.