Which of the following methods is not used as a method to measure the influence of heredity on learning?

Heredity is the sum total of the traits potentially present in the fertilized ovum. All the qualities that a child has inherited from the parents is called heredity.Learning is a complex task that involves many cognitive functions, the brain is capable of learning new skills and concepts throughout life, interacting dynamically with the environment. Biologically, learning capacity allows behavioural responses to adapt progressively, modifying aspects that may favor the survival of the individual in a complex, dynamic and changing environment. Scientists have developed a number of methods to measure the influence of heredity on learning:-Cytological Studies Breeding Experiments Twin StudiesAdoption of studiesTwin study:- It is a method to measure the influence of heredity on learning.Twin studies are a special type of epidemiological study designed to measure the contribution of genetics as opposed to the environment, to a given trait. The close resemblance of twins has been the subject of many works of fiction as well. Twin studies provide a strong basis for exploring the importance of any potential risk factors on a trait or condition by controlling the genetic variations. It has been one of the favourite research tools of behavioural geneticists and psychologists for a long, mainly utilized to estimate the heritability of traits and to quantify the effect of a person's SHARED environment (family) and unique environment (the individual events that shape a life) on a trait. 2. Study of adoptees:-Researchers use ADOPTION studies to determine the contributions of genetic and environmental factors to the development of alcohol problems.Adoption studies are a powerful tool for evaluating the interactions of genetic and environmental factors in eliciting human characteristics, such as intelligence (i.e., IQ), and disorders, such as alcoholism. The relative importance of “nature” (i.e., genetic inheritance) versus “nurture” (i.e., the rearing environment) in human behavior was first debated at the BEGINNING of this century. The strength of the adoption design—separating genetic from environmental influences on a person’s development—results from removing the child (ideally at birth) from the birth parents and their environment into a different environment with biologically unrelated adoptive parents.It is also a method to measure the influence of heredity on learning.​ ​ 3. Free association:-Free association is a practice in psychoanalytic therapy. In this practice, a therapist asks a person to freely share THOUGHTS, words, and anything else that comes to mind. The thoughts need not be coherent.In traditional free association, a person in therapy is encouraged to verbalize or write all thoughts that COME to mind. Free association is not a linear thought pattern. Rather, a person might produce an incoherent stream of words, such as dog, red, mother, and scoot. They may also jump randomly from one memory or emotion to another. The idea is that free association reveals associations and connections that might otherwise go uncovered. People in therapy may then reveal repressed memories and emotions.Thus, it is concluded that free association is not used as a method to measure the influence of heredity on learning.