Through his studies of many diverse Western and Eastern cultures—including the isolated Fore tribes of Papua New Guinea, who could not possibly have learned these facial expressions from the media of another people—Ekman found universal facial expressions for joy, anger, fear, disgust and sadness.

A person's sexual orientation describes the kind(s) of person they find themselves romantically/sexually attracted to. People who identify as heterosexual are attracted to members of the opposite gender, while homosexuals are attracted to people of the same gender. People who identify as bisexual are attracted to both males and females, and those who identify as asexual are not attracted to anyone in that way.

The false consensus effect describes how most people believe that other individuals have a similar mindset as themselves. This is a popular term in social psychology, along with concepts such as groupthink and group polarization.

The cocktail party effect is being able to listen to one voice amidst other voices and distractions. This term comes from the fact that cocktail parties often involve large conversations, during which you may wish to focus on one particular person's commentary.

By Mary Ainsworth, the Strange Situation Test is used to assess the various types of attachment. In the Strange Situation Test, infants or young children are put in a room with their caregiver. Secure attachment between the caregiver and child provides the base for the child's exploration. Upon leaving the child with a stranger in the room, Mary Ainsworth could assess the attachment between the caregiver and child.  

If the child cries when the caregiver leaves and is relieved when they return, the attachment is secure. If the child cries when the caregiver leaves and continues to cry and resist the caregiver when they return, the attachment is resistant. If the child does not cry when the caregiver leaves and avoids contact when they return, the attachment is avoidant. Resistant and avoidant attachments are usually the result of an inconsistent caregiver.

By Mary Ainsworth, the Strange Situation Test is used to assess they types of attachment. In the Strange Situation Test, infants or young children are put in a room with their caregiver. Secure attachment between the caregiver and child provides the base for the child's exploration. Upon leaving the child with a stranger in the room, Mary Ainsworth could assess the attachment between the caregiver and child.  

If the child cries when the caregiver leaves and is relieved when they return, the attachment is secure. If the child cries when the caregiver leaves and continues to cry and resist the caregiver when they return, the attachment is resistant. If the child does not cry when the caregiver leaves and avoids contact when they return, the attachment is avoidant.  

Resistant and avoidant attachments are usually the result on an inconsistent caregiver; infants and young children learn that they cannot depend on their caregiver to consistently meet their needs. As a result, they are less dependent and attached to that caregiver.

Howard Gardner proposed that humans have multiple intelligences. Rather than having an overarching, general intelligence, he hypothesized that everyone had differing intelligences and gifts in eight specific areas: musical, visual, verbal, logical, bodily, interpersonal, intrapersonal, and naturalistic. According to Gardner, every individual had a unique ratio of these intelligences, each of which he referred to as "the g factor."

There is evidence today that supports Gardner’s theory. The cerebral cortex is divided into many different areas, each a different “Brodmann’s area.” Research shows that each area has different responsibilities. For example, a lack of cells in Brodmann area 24 is correlated with autism, while too many cells is correlated with William’s syndrome.

Evidence for Gardner’s theory can also be found when studying Savant syndrome. Individuals with Savant syndrome generally have low IQs and cannot solve simple problems, but are extremely gifted in one specific area. A Savant individual may not be able to solve a simple math problem like “2+2,” but may easily solve an abstract calculus concept.

The strategy of door-in-the-face is starting with a request bigger than your goal (100 miles to amusement park) and following it with your actual goal (10 miles to the movie theater), so that the real goal seems small and reasonable by comparison. 

Foot-in-the-door is when you begin by getting someone to agree to a smaller request ($10 today) and follow it up with a larger request ($20 tomorrow).

Door-in-the-face is a compliance strategy that describes the phenomenon by which people are more likely to agree to a request if it is preceded by a much larger one. In this case, John begins by asking Mary to write his paper (the large request) and then immediately follows with the request that she edit it (the small request).

Foot-in-the-door is a compliance strategy that explains that once someone can get a person to agree to a small request, that person will be more likely to then agree to a larger request. In this case, Julie asks Jeff to vacuum the living room (the small request), which makes him more likely to agree to vacuum the whole house (the large request).