History & Approaches of Psychology



Behavioral psychology's focus is on observable behavior in humans and how we respond.

Ex: How do we learn to fear particular objects or situations?

Study: B.F. Skinner- Operant Conditioning

B.F. Skinner's study focused on how behavior can be changed or altered by the use of both positive and negative reinforcement. For example, Skinner would show positive reinforcement by placing a hungry rat in a box with a lever in it and as the rat would move around the box, it would accidentally hit the lever which would immediately release a food pellet into a container for the rat to eat. Once the rat was dropped the box a few times, it would soon learn to go straight to the lever. This strengthens behavior because it provides a consequence that the rat finds rewarding, so it learns to keep doing it. On the flip side, Skinner would conduct negative reinforcement by placing a rat in another box with a lever. This lever would send an unpleasant electrical current through the rat. When the rat would move around the box and accidentally hit the lever, it would get a minor electric shock. After being exposed to the shock multiple times, the rat would learn to stay away from the lever. Through negative reinforcement, behavior is able to be strengthened because it removes or stops unpleasant experiences.

Behavior Genetics

Behavior Genetics psychology focuses on how our genes and our environment influence how we act and our differences.

Ex: To what extent are psychological traits such as intelligence, personality, sexual orientation, and vulnerability to depression products of our genes?

Study: Sibling Interaction and Behavior Study (SIBS)

The SIBS Study studies adoptive and biological siblings and parents. It is a longitudinal research study. It's main purpose is to understand how sibling interaction impacts behavior as well as how family environment influences the health of adolescents. This study also looks into the similarities and differences between adoptive and biological families.


Cognitive psychology's main focus is on how we process memories and retrieve them. It's the study of mental processes.

Ex: How our interpretation of a situation affects our anger and how our anger affects our thinking

Study: Ulric Neisser (Perceptual)- Selective Looking (Inattentional Blindness)

Ulric Neisser created experiments to test selective looking. In these experiments he would have people look at "superimposed videos" of different things on a single screen. These people, while concentrating on one event, would miss "surprise novel events" happening at the same time on the screen.


Evolutionary Psychology's main focus is to study how "survival of the fittest" or Natural selection has benefited the survival of genes by the saving of certain traits.

Ex: If a boat was sinking and you had the choice to save a 20-year old or a 40-year old, most would choose the 20-year old because they are more likely to be able to reproduce.

Study: Charles Darwin- Natural Selection

Charles Darwin's theory of natural selection states that organisms with adaptations and traits best suitable for their environment will be more likely to survive and pass those traits on, than an organism of the same species that has less desirable traits.


Neuroscience study's how our bodies and brains stir sensory experiences as well as memories and emotions.

Ex: How do pain messages travel from the hand to the brain?

Study: John Martyn Harlow- The Case of Phineas Gage

Phineas Gage was a railroad worker who suffered a severe brain injury when a tamping iron, over 3 feet long, that he was using to pack explosive powder into a hole blew up. The tamping iron was driven into the left side of his face, through his brain, and through the top of his skull. He lived, but a few months after the accident his family began to notice his personality had changed to where he would become impatient and more violent sometimes. Dr. John Martyn Harlow studied the case and examined the effect severe brain injury had on personality, specifically the frontal lobe. This case provided work for how damage to the frontal lobe can affect mood, behavior, and personality.


Psychodynamic Psychology focuses on how our behavior and personality come from unconscious reasons and drives.

Ex: How can someone's personality traits and disorders be explained by unfulfilled wishes and childhood traumas?

Study: Sigmund Freud and Josef Breuer- Anna O

Anna O came to Josef Breuer for symptoms of hysteria. Her disorder lasted from 1880-1882. Breuer realized that having her talk about her life started relieving some of her symptoms. This cure became known as the talking cure. Freud never met Anna O, but her case was the basis of a book he co-wrote with Josef Breuer called Studies on Hysteria.

Social Cultural

Social-Cultural Psychology studies the varying differences of behavior and thinking through different cultures and experiences.

Ex: How expressions of anger vary across cultural contexts.

Study: The just-world phenomenon

The just-world phenomenon is where most people have a need to believe that the world is equal and fair. The believe that people generally get what they deserve as a result. It helps explain the tendency of people to blame the victim rather than look at the social causes.

Cognition: How Your Mind Can Amaze and Betray You - Crash Course Psychology #15

Cognition Video

Cognition includes: knowing, remembering, understanding, communicating, and learning. Cognition allows us to make sense of the world by forming concepts. Our mind organizes concepts by forming prototypes, mental images or examples of a certain thing. Our cognition helps us with problem solving which we can solve in different ways such as speed and accuracy, trial and error, or algorithms and heuristics. When looking for evidence we stick to trying to find stuff that benefits our hypothesis rather than acknowledging contradictory facts in the conformation bias. When conformation bias take hold you could fall into a belief perseverance where you cling to perceptions even though there is proof against your guesses. Our mental set predisposes how we think. When memories are mentally available, the more we think they will happen again, this is called the Availability Heuristic. Thinking is able to be persuaded by how issues are presented, this is called framing.
Natural Selection - Crash Course Biology #14

Natural Selection Video

Natural selection was coined by Charles Darwin in his 1859 book. It is the most powerful and revolutionary cause of evolutionary change. Natural selection is best described as "survival of the fittest" which is to say that organisms with traits more suitable to survive in their environment are more likely to adapt and survive to continue to adapt and change in the future, whereas those who's traits were not as suitable for their environment would soon die out leaving the fittest variations to survive. There are four principles supporting the theory of natural selection. These include: 1. Different members of a population have different characteristics, 2. Traits are heritable, 3. Populations can have more offspring that resources are able to support, 4. Favorable traits are more likely to be passed on to future generations of offspring.
The Power of Motivation: Crash Course Psychology #17