Final answer:
Serotonin and oxytocin are small peptides that have significant effects on the body, regulating mood, appetite, sleep, social bonding, trust, and maternal behavior.
Step-by-step explanation:
The behavior affects of serotonin and oxytocin show how tiny amino acids and peptides can have significant effects on the body. Serotonin and oxytocin are both examples of small peptides that have important roles in physiological processes. Serotonin is involved in regulating mood, appetite, and sleep, while oxytocin plays a role in social bonding, trust, and maternal behavior.