This question is mostly quoted from *A New Psychology of Women* (2017) by Lips, page 63:

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> Finally, and perhaps most importantly, the studies included in most meta-analyses are based on a narrow range of participants (usually young, North American students) and are not reflective of the populations at large--although this limitation tends to be obscured by the combination of many studies into a single analysis (Halpern, 1995). 
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I mean, this claim is more than 20 years old. Is it true today? Is there a study that examines the demographics of meta-studies at large or something related?
If it is true, is this the case for most psychology research, male-female differences or all studies in the social sciences?