Editing Differential psychology (section)

== Methods of research ==
To study individual differences, psychologists use a variety of methods. The method is to compare and analyze the psychology and behaviour of individuals or groups under different environmental conditions. By correlating observed psychological and behavioral differences with known accompanying environments, the relative roles of different variables in psychological and behavioral development can be probed. Psychophysiological experiments on both humans and other mammals include [[EEG]] and [[Event-related potential|ERPs]],<ref>{{Cite journal |last=Clayson |first=Peter E. |date=2024 |title=The psychometric upgrade psychophysiology needs |url=https://onlinelibrary.wiley.com/doi/10.1111/psyp.14522 |journal=[[Psychophysiology]] |language=en |volume=61 |issue=3 |doi=10.1111/psyp.14522 |issn=0048-5772|pmc=10922751 }}</ref> [[Positron emission tomography|PET]]-scans, [[MRI]], [[functional MRI]], [[neurochemistry]]<ref>{{cite book|last1 = Brady| first1 = ST |author2=Siegel GJ, Albers RW, Price DL.| year = 2012|title = Basic Neurochemistry. McGill Press}}</ref> 
<ref>{{cite book|last1 = Kandel| first1 =  ER|author2=Schwartz JH, Jessell TM.| year = 2000|title = Principles of Neural Science, fourth edition. McGraw-Hill Companies.}}</ref> experiments with [[neurotransmitter]] and hormonal systems, caffeine and controlled drug challenges. These methods can be used for a search of biomarkers of consistent, biologically based behavioural patterns ([[temperament]] traits and symptoms of psychiatric disorders). Other sets of methods include behavioural experiments, to see how different people behave in similar settings. Behavioural experiments are often used in personality and social psychology, and include lexical and self-report methods where people are asked to complete paper-based and computer-based forms prepared by psychologists.