Roger Sperry and colleagues, using a tachistoscope and other instruments, studied patients that had their corpus callosum severed. Their findings demonstrated that information is specialized in the hemispheres of the brain. 

Participants in the line-judgment task were asked to identify which of three lines shown in a series of projected images was the longest while sitting in a room with a group of study confederates whom they believed were other participants in the study. The confederates would unanimously agree on the same incorrect line for a question, forcing the participant to choose between conforming to the majority opinion or trusting his/her own eyes and dissenting.

Participants were more likely to disobey when they were far away from the experimenter or when the experimenter's authority was diminished. They were also more likely to disobey if they were nearer to the suffering victim (really a confederate acting as though they were in pain) or if they had previously observed someone else disobeying.

The IQ test has an average score of 100, with a standard deviation of 15. Scores of 130 or above demonstrate a person with superior ("gifted") intelligence, while scores of 70 or below indicate an intellectual disability. This scale is the same for both the original IQ test, as well as modern iterations.

Milgram is best known for devising an experiment to study how human participants react when they are asked to shock others. Whenever the "learner" got a memory question wrong, the "teacher" was told to administer a shock to a learner located in a different room. Milgram devised this study to examine how so many people participated in the cruel acts of the Holocaust.

Mary Ainsworth was a developmental psychologist who is best known for creating the "Strange Situation" to test infant-caregiver attachment patterns. In brief, the Strange Situation involves the caregiver leaving the infant alone for a short period of time, and then returning. Ainsworth observed the infant's response to the caregiver's return, and classified the response into an attachment pattern.

Case studies are known to examine one individual with the ability to collect very detailed data. Despite the hope of being able to reveal information that may later be true for many people, the ideas and suggestions collected from observing one individual cannot be applied to a population. We cannot be sure that observed principles in a particular case can apply or be true for a population—it could be "an exception to the rule.” For instance, a case study may examine one male individual who smokes and has lived to 110; however, a mass study could have been released that suggests the average lifespan for male smokers to be less than 85. In this instance, the case study was of an atypical example; therefore, it would not be scientifically sound to theorize that all male smokers should have a similar life expectancy based on the information of one extraordinary case.

Surveys provide the ability to sample multiple cases that require volunteers to self-report their opinions and behaviors. This method permits the statistical analysis of the information collected from a wide variety of participants while also covering a broad base of questioning. Subsequently, surveys are not as keen methods of observation as case studies, naturalistic observation, or counseling. These three methods may require a close engagement with an individual in a particular setting; therefore, they provide an opportunity to collect detailed information about one particular individual as opposed to collecting data on massive populations. 

When testing the effects or the relationship between two factors, in this case coconut milk consumption and intelligence, an experiment requires a control and a treatment (experimental) group. The first is the group without the treatment whereas the second is exposed to the treatment (in this case, coconut milk). The two groups should be compared post-experiment after data analysis in order to understand or observe the effects of the treatment relative to standard conditions (in this case, no coconut milk).

The result Rosenzweig and colleagues noted was that the brain weight of the environmentally enriched rats increased over time relative to the impoverished rats. Taking a closer look, they realized that it was specifically the cerebral cortex that had the most significantly noticeable difference. This experiment marked a cornerstone in the “nature vs. nurture” debate where genes ("nature") are said to be be responsible for the brain's blueprints, but experiences ("nurture") fill in the rest—in this case, development and establishing impressive branched neural connections. In order to make sure, Rosenzweig and colleagues repeated the experiment multiple times prior to publishing. This finding has been extended into observing the importance of nurturing in early childhood. This was true for the young rats—as seen in the experiment—and has been noted for young children as well.