approached significancep = 0.061
The interaction effect between attractiveness and valence approached significance [ F (1, 20) = 3.956, p = 0.061], and the P300 was more positive for the fair offers (mean ± SE, 4.823 ± 0.724 μV) compared with the unfair offers (mean ± SE, 2.788 ± 0.758 μV) in the unattractive-face condition ( p = 0.002) but not in the attractive-face condition ( p = 0.413, unfair offers: 3.518 ± 0.768 μV, fair offers: 3.944 ± 0.745 μV).