Does the trust game measure trust?

We test whether altruism is a significant confound of observed choices in the standard trust game. We allow for rich and poor trustees and examine whether, consistent with dominant altruism, trustors give more to the poor, or whether, consistent with dominant trust motives, trustors give no more to the poor than to the rich. This test is based on within-treatment and within-subject comparisons. Our results support trust as the dominant motivation for 'trust like' decisions