On not testing the foreign-language effect: A comment on Costa, Foucart, Arnon, Aparici, and Apesteguia (2014)

TL;DR

This paper critiques prior research on the foreign-language effect, highlighting that the original studies failed to statistically test the effect's existence, leading to potentially invalid conclusions.

Contribution

It demonstrates the importance of proper statistical testing for the foreign-language effect and reanalyzes original data to correct previous methodological oversights.

Findings

Four out of five studies' conclusions are invalid due to improper testing.

Proper statistical comparison shows no significant foreign-language effect in most cases.

Highlights methodological issues in previous foreign-language effect research.

Abstract

In their first five studies, Costa, Foucart, Arnon, Aparici, and Apesteguia (2014) fail to provide a statistical test of the foreign-language effect. Instead, the authors employ a procedure in which they test the framing effects separately for the native and the foreign language conditions. Such a procedure, however, is inappropriate when comparing two effects; rather, a test of their difference is required. Using the original data, it is shown that in four out of the five studies the authors' conclusions about the existence of a foreign-language effect are invalid.