#twin-studies

#twin-studies

Until 2007, Sweden maintained a wealth tax that required citizens to disclose their financial holdings. That created one of the deepest household-level investing datasets ever assembled, allowing researchers to study actual portfolio behavior rather than relying on surveys or self-reported answers.

Now, new research from Horvath and Fabricant challenges that assumption, and it does so with the kind of study design psychologists dream of: examining identical twins reared apart. Their findings suggest that education, of all things, may hold surprising power to raise measured intelligence. For educators, this study could be a validation of an instinct we've tapped on for years. For the rest, it offers hope that misreadings of prior research had closed off.