A **stimuli** is any signal that brings information to our body, hence resulting in a specific response. Animals including us humans respond to various kinds of stimuli made by the external environment, and our responses are made possible because of these three primary body systems– **sensory system which includes our sense organs**, **nervous system**, and **muscular system**.

**Innate Behavior** – Behaviors that are performed ideally the first time they are used, even though the animal may never have had the experience with the stimuli which caused the behavior.

**Learned Behavior-** are conditioned responses that animals build up over time to certain, specific stimuli.

Innate and learned behaviors are both responses to stimuli, however, innate behaviors are behaviors that the animal does not have to be taught in order to perform. Learned behaviors must be taught over time.

Learning is also referred to as **acquired behavior** because the knowledge is being acquired and developed through experience over time. There are four major types of learning and they are, **habituation, classical conditioning, operant conditioning**, and **insight learning**.

1. **Habituation** is the simplest form of learning. It is the process in which there is a decrease in an animal’s response after repeatedly being exposed to a stimulus that has no positive or negative effects.

2. **Classical conditioning** occurs when there is an association made between two different kinds of stimulus (ex. Pavlov`s experiment in dog -food and bell association). Anytime

3. **Operant conditioning** is when an animal learns to associate its response to a stimulus with a reward or a punishment.

4. **Insight learning** is a type of learning in which the animal applies the behavior it has learned to a given specific situation without the premise of trial and error.

– Stimulus
– Something that causes a response. It can be controlled by external forces such as an experimenter.

– Response
– A behavior that results from the introduction of an external stimulus.

Stimulus and responses are different in that a stimulus is an external environmental factor that may or may not be controlled. A response is an internal behavior that is either learned or innate and cannot be controlled.

Natural Selection is the process in which animals that are least likely to survive will be eliminated from the population together with its gene pool. This process also results in the adaptation of some organisms to a given environment resulting in their survival.

Animals that adapt through learned behavior will pass on these behaviors to the next generation. Natural selection will then begin to weed out those animals that have not learned the behavior until it has become innate.

Here are some examples of classical conditioning:

When you smell the perfume that your mother has sprayed, you usually associate the scent with her. The next time you smell the same scent, you tend to remember your mother.

After eating a crab, you immediately felt a shortness of breathing. It turns out that you are allergic to it. The next time you see a crab, you tend to avoid eating it because you have already learned that you are allergic to it.