How Needs-Supplies Fit Processes With Teachers, Peers, and Parents Relate to Youth Outcomes: A Theoretical and Methodological Extension of Self-Determination Theory

It should be noted that the issue of individual differences in needs differs substantively from the issue of universality of basic psychological needs in human beings, also assumed within SDT (i.e., Proposition III of BPNT; Ryan & Deci, 2017). The issue of universality relates to cross-cultural variations in the personal endorsement of needs satisfaction, that is, the degree to which one desires or seeks to satisfy these needs (i.e., needs strength, needs desire). Such cross-cultural variations in personal endorsement of needs have been shown not to affect the actual effects of needs satisfaction on wellness, thereby corroborating the universality of these needs for psychological functioning (Chen et al., 2015). The issue of individual differences in needs relates, instead, to the degree of support intake that is perceived to be necessary to create needs satisfaction, while assuming needs satisfaction effects are universal (i.e., independent from the personal endorsement of needs). Investigating individual differences in needs is therefore fully compatible with the universality assumption of BPNT (see also Núñez-Regueiro, Juhel, et al., 2024).

The first reversal point was negligible, being situated at extremely low N-S values; i.e., \({{needs\; TAS}}_{r1}={{supplies\; TAS}}_{r1}=-3.218\) (see Fig. 3B).