> Of the 87 pairs, 52 experienced a similar type and duration of schooling within a similar location. In fact, 25 of these pairs attended the same school for some period of time. Analysis revealed that ‘Educationally Similar’ TRA pairs have an ICC of 0.87 ± 0.02 (n = 52)

So this study has 87-52-25=10 data points? Am I reading this correctly? Quite the reach to conclude what the article claims, if so.

> With this said, it is important to note that the ‘very dissimilar education’ group consisted of only 10 TRA pairs. This small N is not a shortcoming of this analysis, per se. Rather, this is a shortcoming of the TRA field; these 10 pairs represent the entirety of individual data published over the last century.

Authors plead innocence!

I read the quoted sentence as "25 of the 52" -- not an additional 25 of the 87 -- because of the word "these".

52 pairs similar schooling 25 of these had very similar schooling

Thus the math becomes "87-52=35". 35 data points. Not spectacularly high regardless.