Subjective ratings
In line with pupil dilation findings, we observed a main effect of Hand type [F(1,119) = 32.062, p < 0.001, η2 = 0.212], indicating that participants preferred to receive a touch from a Human hand than from an Artificial hand [t(119) = 5.662, p < 0.001]. Also, we found a main effect of Touch type [F(1,119) = 15.087, p < 0.001, η2 = 0.113], indicating that participants preferred to receive a touch with a CT-optimal than a CT-suboptimal speed [t(119) = 3.884,p < 0.001]. Finally, we also found a significant Hand type by Touch type interaction [F(1,119) = 7.402,p = 0.044, η2 = 0.034], which showed that participants preferred to receive a CT-optimal touch from a Human hand. Indeed, post-hoc pairwise comparisons showed that the CT-optimal touch from a Human hand condition received the highest ratings compared to all other conditions [CT-optimal_Human vs. CT-optimal_Artificial: t(119) = 3.657, p < 0.001; CT-optimal_Human vs. CT-suboptimal_ Human: t(119) = 2.343, p = 0.021; CT-optimal_Human vs. CT-suboptimal_ Artificial: t(119) = 7.070, p < 0.001] (Figure 2e ). These results, in line with physiological findings, indicate that a touch is perceived as the most pleasant when is promoted by a Human hand and with CT-optimal speed.