A middle-aged woman enters a supermarket with a list of five items. However, she leaves with twenty products in her shopping cart, including an ice cream she hadn't planned on taking home. What happened here? The bright colors of the packaging, the store's music, the strategic placement on a shelf near the checkout, and María's mood (she was feeling a bit down that day, to be honest) all influenced her decision—or rather, decisions—without her even realizing it.

This example clearly demonstrates how multiple psychological factors play a role in a purchasing decision. Consumer psychology is a specialized branch of applied psychology that focuses on studying and understanding how people think, feel, and act in their role as consumers. This discipline, which combines principles of cognitive, social, and behavioral psychology, examines the mental and emotional processes that influence purchasing decisions, including aspects such as motivation, perception, memory, and learning, as well as the social and cultural factors that affect consumer behavior.