The response model is founded on three basic theories that explain the time pattern of the effects of drugs and the differential reactivity to them, i.e., the opponent-process theory of acquired motivation of Solomon and Corbit (1974), the gated dipole theory of Grossberg (2000) and the UPTT of Amigo (2005).
Equations (32.ij) represent the second extension of the UPTT towards a unified dynamic theory of personality given by the response and bridge models.
On the other hand, let us recall that we left from the UPTT, whose fundamental postulate is (Amigo, 2005):
The UPTT proposes a hierarchical model of personality where the highest level corresponds to the GFP which includes the B5F.
Thus, following Postulates 1, 2 and 3, the UPTT can be considered as a unified dynamic theory of personality.
* A fundamental hypothesis of the UPTT is that personality has a dynamic character, thus a dynamic model is needed.
All these results are congruent with the UPTT presented in the Introduction.
The UPTT predicts that high sensation seekers (with a significant difference between the SS-T and the SS-S) would present a higher phasic response to a stimulant than low sensation seekers, which is precisely what the results reveal.
The effect of coffee is measured by the Sensation-Seeking Scale of the MAACL-R, related with the GFP, which is representative of the individual activation level whose biological basis, following the UPTT, is the general activation or extraversion (Amigo, 2005; Amigo et al., 2008a; Caselles et al., 2010).
These outcomes are consistent with the UPTT. A high trait level means a low activation level in a weak stimulation situation (on an empty stomach in the morning).
In addition, the UPTT states that the biological base of the GFP or extraversion is the stress system (Amigo, 2005; Amigo et al., 2008a).