Many human characteristics, like height, are shaped by both nature—in other words, by our genes—and by nurture, or our environment. For example, chronic stress during childhood inhibits the production of growth hormones and consequently reduces bone growth and height. Scientists estimate that 70-90% of variation in height is due to genetic differences among individuals, and 10-30% of variation in height is due to differences in the environments that individuals experience,...

Memory is one of the most vital higher mental functions of the brain. Memory is closely related to learning because it enables us to retain information and experiences from our past to use them in our present life. It also helps us to remember facts, events, and skills, such as riding a bike or swimming. There are two types of memory — declarative memory, which involves memorizing facts or events, and procedural memory, which enables us to remember how to do something like writing or...

Consciousness can be defined as the state of being aware of and able to think about one's existence, sensations, and surroundings. It encompasses two major components: awareness and arousal. Awareness pertains to the recognition of environmental stimuli and internal states. At the same time, arousal refers to the physiological readiness to engage with these stimuli, which varies significantly between states like sleep and wakefulness.
Sleep, a crucial state, is characterized by reduced...

Learning is the process of acquiring knowledge or skills through practice or experience, leading to long-lasting behavioral changes. This acquisition occurs through interaction with the environment and requires practice or experience. For instance, mastering a skill such as surfing requires considerable practice and experience, highlighting the essential role of repeated interactions with the environment in learning.
In contrast to learned behaviors, unlearned behaviors such as crying, sexual...

E. C. Tolman emphasized the purposiveness of behavior — the idea that much of our behavior is goal-directed. For instance, employees who aim for a promotion work diligently to meet their targets. Tolman argued that when classical conditioning and operant conditioning occur, the organism acquires certain expectations. In classical conditioning, a child might fear a dog because they expect it to bite. In operant conditioning, a person might consistently work overtime because they expect a...

Instinct theory proposes that innate biological instincts, like animal behavioral patterns, primarily drive human behavior. These instincts are inborn, not learned, and are fundamental to decision-making and action. Just as animals rely on instincts for critical survival functions such as migration, nest building, and defense, humans are also believed to exhibit behaviors rooted in evolutionary needs. For example, the instinct to reproduce motivates sexual behavior, while territorial instincts...