Dr. Mitchell is conducting a research study on temperament. As a basis of this study, he plans to follow 1,000 subjects from the age of 5 to the age of 35. At periodic times he will revisit subjects and their temperament. Dr. Mitchell’s research study is planned to last for 30 years. Which of the following best describes the type of research Dr. Mitchell is conducting?

a. ethnographic research
b. quasi-experimental research
c. longitudinal research
d. cross-sectional research

Longitudinal research

Explanation:

Longitudinal research is research that is based on a long period. In this research, the information or the data is collected on the bases of a period of the same population. This period is extended over time. The cohort studies are common in medicine, psychology, and sociology many psychologists conducted a study based on longitudinal. There are many examples like Canadian study conducted on population.  

Thus here Dr. Mitchell has conducted a research study on temperament. He has conducted a research study on temperament that is longitudinal research.

intimacy, passion and commitment are the components of a interpersonal relationship emphasized in the triangular theory of love by robert sternberg.

the triangular theory of love says love can be comprehend as this componest form the vertices of a triangle.  

intimacy relates to feelings such as of closeness and connection;

passion relates the drives that brings people together, as physical attraction.

commitment relates to the being in a long-term relationship.