Associationism is a psychological theory that suggests our thoughts and behaviors are formed through associations between different ideas, experiences, or stimuli. This means that when we encounter something new, we connect it to previous knowledge or experiences, which helps us understand and remember it better. The concept is closely linked to the work of philosophers like Aristotle and later psychologists such as John Locke and David Hume. They proposed that learning occurs through the formation of connections, or associations, between sensory experiences, leading to the development of complex ideas and behaviors over time.