Following a Noam Chomsky "nativist" perspective regarding universal grammar, Dr. Lengua thinks people are born with the ability to communicate regardless of their environmental influences. Social interactionist perspective is the opposite view in that individuals learn language and communication through modeling, dialogue, and corrective feedback. Behaviorist and sociocultural are distractors. 

There are approximately 30,000 genes in the human genome. These genes influence many traits including physical and psychological characteristics. Some genes can influence multiple traits, while others influence only a single trait. It is important to understand that the biological basis of genetics in order to fully understand psychology. 

Behavioral genetics examines how genes and environmental factors influence behavior. Behavioral genetics often involves twin studies and focuses on three primary factors. First, they study what is known as additive—or shared—genes associated with the trait being examined. Next, they examine shared environments. Finally, behavioral genetics also examines non-shared environments. These three components help to explain the extent to which the presence of a particular trait is due to genetic or environmental factors.  

"Heritability" describes the amount of variance in a trait that is controlled for by genes. For example, height has a high heritability because it is almost exclusively influenced by genes, not the environment. Some psychological traits can have high heritability too. For example, substance abuse problems often run in families. Behavioral genetics has determined that substance abuse problems can be around 50% heritable. This means that even though a child grows up in a drug-free environment, they may still be at risk for inheriting the trait from biological factors. For example, if one of their biological parents had experienced substance abuse issues, then the child could be at risk at also developing them later in life.

"Family socioeconomic status" is an environmental factor that has strong influences on several behavioral and developmental traits. Anything that is biologically passed down like a familial disorder or certain genetic trait would fall into the genetic category. Anything that is not determined by biology but by situation or life experiences falls into the environmental category.  

Environments that are experienced by all siblings in a family and have similar effects on all the members of the family are considered to be shared environments. Family income would exert similar pressures and experiences on all the siblings in a family. Behavioral genetics studies siblings (often twins) in order to observe the relationship between genetic and environmental factors. They do this by isolating environmental variables. For instance, if psychologists know whether or not siblings possessed a shared environment, then they can determine what traits are most influenced by specific family characteristics and what traits are most influenced by environmental factors outside the home. 

Environments that are unique to individuals or those that are experienced differently by each sibling will have varying effects on each sibling. Being treated differently by their parents would create different environments and have different impacts on the behavior of siblings in a family. Non-shared experiences can influence many factors of a child's personality and differentiate them from their siblings. Anything that a person experiences uniquely qualifies as a non-shared environment. 

Chromosomes are made up of DNA and store the genetic material of an individual. Chromosomes are found in the nucleus of human cells and contain all of our DNA. Genes are found in specific loci (locations) on chromosomes. These terms are commonly used in many areas of psychology that use genetics to describe certain behaviors or outcomes. 

"Alleles" are the different versions of a gene. Alleles can have varying patterns of inheritance like dominant alleles and recessive alleles. They can be found at the same location on a specific chromosome. 

Humans have a total of 23 chromosomes. 22 of them are autosomes, or non-sex chromosomes, and 1 pair are sex chromosomes. Autosomes are chromosomes that control traits like skin and hair color. Sex chromosomes determine things like gender and different gender characteristics.