Hormones are involved in building up motivation in animals. This has been confirmed in several experiments where hormones have either been injected into these animals or where the endocrine organs have been removed.
How exactly do hormones influence behavior? The answer to this question is supported by these possibilities that are backed by evidence.
(i) Hormones may alter the sensitivity of peripheral receptors. This can be observed in rats where the male hormones enhance the sexual behavior by raising the sensitivity of the penis.
(ii) During an animal’s development and even at adulthood, hormones can affect the growth of nervous connections in the brain.
(iii) Hormones can directly affect nerve cells and synapses within the Central Nervous System(CNS). In this way, they may block inhibitory pathways or open up excitatory ones within this system.
(iv) Hormones may directly influence the performance of effectors, either by enhancing or suppressing them. In some extreme cases, a hormone can actually cause degeneration of a muscle culminating in the degradation of a particular response in its entirety.