Introduction: Two principles that define the biological level of analysis are that patterns of behavior can be inherited and that animal research may inform our understanding of human behavior.
Patterns of behavior can be inherited
• MzTwins: when tested on temperament and IQ, their results were very similar – more similar than DizTwins • Adopted children: their temperament was more like that of their biological parents than their adoptive parents
Animal research may inform our understanding of human behavior • Meaney’s experiment with rats: the less touch they experienced, the more elevated their levels of glucocorticoids; this killed brain cells, thus they were less clever and not as fast at solving problems So perhaps raised cortisol is also detrimental to human learning and memory • Sperry and Gazzaniga’s split brain study: they severed the corpus callosum of cats and monkeys to experiment and found that there was no huge effect on behavior They decided to try it on people with epilepsy, and they also showed few effects
Discuss how and why particular research methods are used at the biological level of analysis (for example, experiments, observations, correlational studies).
Introduction: Two research methods that can be used at the biological level of analysis are experiments and case studies.
Experiments are research methods in which an investigator manipulates one or more factors (independent variable) to observe the effect on some behavior or mental process (the dependent variable) How: Experiments are used to determine cause and effect in many different situations in biology – from figuring out localization of function, to determining the effects of the environment on physiology, discovering the effects of hormones, and many other factors. Some experiments are done on animals, some on humans. • Rosenzweig et al’s study on rat environments: question whether certain experiences produce physical changes in the brain Independent variable: environments (typical laboratory cage, “enriched” environment cage, “impoverished” cage) Dependent variable: autopsies of rats’ brains (brains were dissected, various sections measured, weighed, and analyzed to determine the amount of growth and levels of neurotransmitter activity) Results: rats who lived in the “enriched” environment had thicker/heavier cerebral cortex, larger neurons, greater ratio of RNA to DNA Why: Allows scientists to investigate one factor that affects the subject. It is also the only method that allows us to determine cause and effect.
Case Studies involve studying one person or group in depth in the hope of revealing universal principles. How: Case studies are often used to study individuals with disabilities or unique circumstances. • Broca’s study on Tan: loss of speech – unable to produce language Studies while he was alive show the extent of his disabilities Post-mortem studies showed chronic softening and partial destruction of the anterior left lobe of the brain • Phineas Gage: frontal lobe damage can alter personality, removing a person’s inhibitions A rod shot up through his left cheek and out of the top of his skull, leaving his frontal lobe massively damaged Became irritable, profane, and dishonest
Mental capabilities and memories were intact, but his personality was not Why: You can’t experiment on people and cause damage, but when this happens naturally, it can be useful to learn from.
Discuss ethical considerations related to research studies at the biological level of analysis.
Introduction: Research studies done on...