The association between General Mental Ability (GMA) and whole brain size was almost accepted universally. Association between the Performance Intelligence Quotient (PIQ) score with anatomical characteristics such as gender, height, weight, and brain size are also focused on many research articles. However, very little study has been made to establish the association of PIQ with physical characteristics, Full Scale IQ (FSIQ), and Verbal IQ (VIQ). The present paper aims to establish the association of PIQ with physical characteristics, FSIQ and VIQ. It is derived that PIQ is heteroscedastic random variable, and its mean is positively associated with FSIQ (P < 0.0001) and brain size (P < 0.0001), while it is negatively associated with VIQ (P = 0.0001). Variance of PIQ is negatively associated with FSIQ (P = 0.0634), brain size (P = 0.0240), and gender (P = 0.0992). PIQ is also independent of height, weight, and body mass index. PIQ is higher for the individuals who are having higher FSIQ, larger brain size and lower VIQ.