# Developmental psychology/Chapter 1/What is Developmental Psychology?

Developmental psychology is a field where scientific paradigms collide. Although each of us has an intuitive understanding of the definition of development, researchers have to carefully define their field of study. For some, that definition is rooted in biology and relates to reaching sexual maturity. For others, however, the definition of development is more closely tied to the concept of change and is viewed as happening over the lifespan. Thus, something as simple as a definition is deeply tied to philosophical perspectives on the world and on research.
Although against some people's views, developmental psychology is a science. This is because it is similar to other sciences: it relies on data and analyses to discover facts and evidence to back up certain claims. An example of a developmental psychology topic that can be researched which proves that this is science is which method of discipline is best for children. Is beating your children a secure way of disciplining them or is it child abuse? Some countries take the practice as a norm, while others may take it as child abuse. Which one is backed up by scientific evidence?

## Scientific Method

The scientific method is the empirical method of obtaining knowledge in the field of science. While analyzing results, we measure them through different statistical measurements.
* Effect Size - Cohen's d. On a scale, .2 is small, .5 is moderate and .8 is large.
* Significance - Shows whether results occurred by chance. A significance test of .05 means that in 5 times in 100 chances, those certain results would occur.
* Cost-benefit analysis - Calculates how much an IV costs vs. how much the IV saves (good for public spendings).
* Odds ratio - How a specific variable compares to a set of 1 (a standard).
* Factor analysis - Basically shrinks a huge chunk of data into a smaller, more significant group of data.
* Meta-analysis (based) - Studies previous studies, weighs the results fairly and comes to conclusions based on those results.
Scientific observation is the act of analyzing subject's behavior either in their natural habitat or in a laboratory. Observation is crucial for the scientific method as this is where we come up with our questions. For example, what is the impact of parents staying with their children for too long before their first day of pre-school? Studies showcase that parents that stay longer than 3 minutes negatively impact their child's performance in school. But is it because of the parents or is it because their child is naturally shy? This is why in observation correlation does not equal causation.
An experiment is where the hypothesis is put to the test. Here, the experimenters change the Independent Variable, the imposed alteration, and see if it affects the subjects (dependent variable). The purpose of an experiment is to see the affect of the IV on the DV. Typically, the experimental group is what is tested on while the control group receives no treatment so that a comparison can take place.
* Curiosity
* Create a Hypothesis
* Test the Hypothesis
* Collect and assess data
* Conclusion
* Replication

### Nature vs. Nurture

* Nature - Person's character is based on genes
* Nurture - Person's character is based on environment
It is not a question of "which?", but "how much?" [but even this may be misleading as it isn't like they both contribute a fixed amount, they both have their explosiveness's and both respond to each other's explosiveness when prompted]. Both play a role in a child's development and neither one takes 100% accountability. They both affect each other.

###### Definitions To Remember

* Epigenetics is a disciple that deals with how the environment [nurture] affects one's genes [nature].
* Differential Susceptibility is the difference in peoples' sensitivity to different experiences based on their genes or past incidents. An example is listed below from a Quizlet deck.
** Q: How might differential susceptibility apply to understanding students' varied responses to a low exam grade?
** A: Differential susceptibility can help you understand why some students will take a low exam grade very hard and feel life a failure vs. some students who brush off a low exam grade and know better for next time.

### Data Collectment
#### Survey

A survey is a direct way to gain data from people often by asking them 'at the spot'. Unfortunately surveys are not accurate because of liars and/or wording (global warming vs. climate change). Some people don't want to be honest or they want to answer the way the researcher wants them too (biased website hosting polls, for example).

#### Studying Development over the Life Span

Developmentalists aim to observe the change in people over time (change or no change). To record these dynamics, researchers use either cross-sectional, longitudinal, or cross-sequential.
* Cross-Sectional - This is the easiest and least expensive way out of all of the 3 methods. This is where a cohort of the one age is compared to a cohort of another age. This may seem simple, but it is very difficult to get two cohorts who are the same in every aspect except for age.
* Longitudinal - This is tracking of the same cohort over an extended period of time. For example, due to the scientific evidence discovering the adverse effects of being obese, a cohort of people who were obese when younger may lose weight and become of normal weight when they become adults. The longitudinal observation of that cohort will only prove this hypothesis. The issue with longitudinal data is that culture changes over time (for example, smoking culture), very expensive, and participants may drop out over time. The benefit of this study is that differences that occur over time can be easily observed (we can figure out why these differences took place!).
* Cross-Sequential - Combines both strategies above. Here, scientists study people of different ages (cross-sectional) and follow both of them for an extended period of time (longitudinal).

## What is "developmental"?

Development in a human being is multidirectional, multi contextual, multicultural, multidisciplinary and plastic.

### Multi-Directional

Development is multi-directional. Some traits disappear, appear, increase/decrease throughout our life. Some will stay for good, like our zygotes. Some are continuity, such as trees growing for centuries, while some are discontinuity, such as caterpillars becoming butterflies.
* Critical periods - Periods where growth MUST occur. For example, the critical period for humans to grow limbs is 28-54 days after conception. This was found out after pregnant women took a drug, thalimode, in the 1950s and their offspring produced abnormalities in limb growth.
* Sensitive periods - Periods where a particular development could occur, but can take place at a later time. An example is an immigrant from Iraq. The parents immigrating will speak English with an accent while their newborn children (who've arrived freshly to America) will learn English unaccented.

### Multi-Contextual

Development is multi contextual. The setting matters: the environment, the events taking place during that situation, population density, etc. Social contexts are crucial to a person's decision-making.
Socioeconomic influence (SES) brings opportunities, as well as limitations: housing, health, nutrition, etc. Low income inhibits a person but can be changed through a person's education or influences. People with no college degrees are more likely to be poor (per statistics).

#### Ecological-systems Approach

Developed by Urie Bronfenbrenner (1917–2005), the Ecological-systems Approach method aims to analyze all different levels of influences on a person's development. They are as follows:
* Microsystems - One's immediate surroundings, including the family at home and close friends.
* Exosystems - One's larger surroundings, such as school or the football pitch (if they play football on the daily, for example).
* Macrosystems - One's largest surroundings, including political environment and ethnic culture.
Other systems are chronosystem [chrono --> time], which details the historical context (names for babies, such as "Emma" [new] and "Mary" [old]), and mesosystem, the connections between all the systems (religious values, mass media, medical institutions, transportation system).
Cohorts (people born in a similar time period and move together) play a role as well. Marijuana was popular until 1980, when the "War on drugs" took place and prohibited people to own ounces of weed. After 1990, attitudes changed and now it is popular again, including 12 US states allowing the medical use of it [2017] (and more states allowing the use of marijuana, VA being a recent state [2021]: see here).

### Multi-Cultural (review)

For scientists in a scientific term, someone's "culture" is someone's "set of beliefs, traditions, practices that are in existence for a certain period". Culture is an example of a "social construction", a heap of perceptions that affect the way people act. Some people may mistakenly believe that a characteristic of themselves that is away from the norm is a "deficit", which is called difference-equals-deficit error.
Ethnic group - People whose ancestors were born in the same area. Usually share religion, language, and nationality. They are usually social contracts (Africa in the USA [Nigerian] vs. Africa in Africa [Nigerian --> Yobo]). The race is also a social contract as well.

### Multidisciplinary Approach

Incorporating many approaches to a certain problem that are usually outside of the norm.

### Plasticity

The real meaning of plasticity is the ability to change but still maintain something. This proves two statements:
* Change is possible
* A person is built off of their past events
An example of plasticity is treating autistic children. Although their autism will not leave (built off of past events), they will improve their motor skills (change).
The dynamic-systems approach supports the notion that human development is a constant pot of interactions between the human and the physical, cognitive, and psychosocial influences.

### Analysis of David's Case Study
## Ethical Standards

When conducting experiments, the experimenters must adhere to strict regulations. They must ensure that:
* all participants are safe and well (example, the w:Nazi human experimentation wouldn't have passed this)
* all participants consent to the experiment
* all information is confidential
* no participants are seriously harmed or injured
Most institutions have an Instructional Review Board (IRB) which assesses whether an experiment can be conducted or not.