Step 1: Match each concept properly.
- P. Instinct → (ii) Are fixed action patterns (Inborn, automatic behaviors).
- Q. Incentive → (i) Environmental motivation triggers (External rewards influence behavior).
- R. Self-actualization → (iv) Considered by Maslow as the highest need (Growth to full potential).
- S. Intrinsic motivation → (iii) Self-determination theory (Doing activities for inherent satisfaction).
Thus, the correct matching is:
\[
\boxed{{P-ii; Q-i; R-iv; S-iii}}
\]