In other words, it is the graph of Ss′/O′, where Ss′ is the normalized value of the severity of the autism obtained from the least squares calculation of the NEPSYS theory of mind score corresponding to each oxytocin concentration in the range given in Table 2 above of 0 pg/ml to 9 pg/ml, and O′ is the normalized value of the oxytocin concentration. Here, OXT is linked to autism.