Doesn't appear to have held up to replication. [1]

>However, unlike Tsukuhara et al., we could establish only small to nonexistent associations between cognitive ability and pupil size (r’s -.01 to .06, r with g specifically = .05)

In fact, a quick scan down the Scholar results shows other replications have found the opposite effect [2]

>The results found that high-Gf adolescents showed smaller tonic pupil size in both tasks

[1] https://www.researchgate.net/profile/Emil-O-W-Kirkegaard/pub... [2] https://onlinelibrary.wiley.com/doi/epdf/10.1002/pchj.397