Father-father interactions positively influence fathers themselves and their family. This study aimed to develop scales to measure father-father interactions. One hundred and five fathers were preliminarily surveyed, and the actual state of father-father interactions was identified using the bottom-up method. Three hundred and twenty fathers participated in the main survey. Exploratory factor analysis yielded two subscales: a Father-Father Activities Scale (FFAS) with the two factors of “leisure activities” and “school activities” and a Father-Father Topics Scale (FFTS) with the 3 factors of “child-rearing topics,” “personal topics,” and “family topics.” The internal consistency of each subscale was confirmed. A significant correlation between the subscales and a belief in cooperation, an affiliative tendency, and friendships was noted. In addition, differences in FFAS and FFTS scores by the father’s basic attributes were examined. In conclusion, the FFAS and FFTS measure father-father interaction, and their reliability and construct validity were confirmed.
