1. Answer;
Single case study.
Step-by-step explanation;
Researchers may use many different designs and methods to study human development. The most popular design are cross-sectional, longitudinal and the cross sequential.
Cross-sectional design involves the number of different-age individuals with the same trait or characteristic of interest are studied at a single time.
Longitudinal design involves the same individuals being studied repeatedly over a given period of time.
Cross sequential design involves individuals in a cross-sectional sample that are tested more than once over a specific period of time.
2. Answer;
The interaction of nature and nurture
Psychologist believe that the interaction of nature and nurture is/are most likely responsible for influencing but not determining your future behaviors.
Explanation;
Nature and nurture are essential for any behavior.
Genetic and environment are the key elements that determines a given characteristic in an individual.
The nature and nurture may influence the trait of an individual but may not influence or determine the future behaviors