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Scripture • James 1:5-6 If any of you lack wisdom, let him ask of God, that giveth to all men liberally, and upbraideth not; and it shall be given him. But let him ask in faith, nothing wavering. For he that wavereth is like a wave of the sea driven with the wind and tossed.
Genetic Influences on Behavior • Phenotype • The visible and measurable traits of an organism • Genotype • The underlying genetic composition of an organism
Genetic Influences on Behavior • The basic biochemical unit of inheritance is the gene. • Gene • The basic biochemical unit of inheritance that is located on and transmitted by chromosomes • Chromosomes • Thread like structures carrying genetic information that are found in every cell of the body • Deoxyribonucleic acid (DNA) • The complex molecule strand of the chromosome that contain thousands of different genes, located at fixed positions • Sex Chromosomes • One of the 23 pairs of chromosomes that determines whether an individual is male of female
GENES: The Building Blocks of Heredity and Development Genes are parts of DNA molecules, which are found in chromosomes in the nuclei of cells. DNA (Deoxyribonucleic Acid)
Chromosomes are made of DNA, which are made of genes. Chromosome: threadlike structure made largely of DNA molecules DNA: a spiraling, complex molecule containing genes }
Chromosomes and Inheritance • The human genome includes 46 chromosomes in 23 sets matched sets; each chromosome has the same gene locations. • This includes the X and Y chromosomes, not a matched set in males, who are missing some genes on the Y. • A biological parent donates half his/her set of chromosomes to his/her offspring. • We received half a set of chromosomes from each biological parent.
In the Beginning was Information --- Question from a student on the Human Genome Project website Answer from a human genome researcher Who determines the “proper order”? What do adenine-thymine base pairs have to do with making proteins? Plans imply encoded information put there by an Intelligent Designer!
The Human Genome:20,000 to 25,000 Genes The genome: an organism’s entire collection of genes • Human genomes are so nearly identical that we can speak of one universal human genome. • Yet tiny genetic differences make a difference. If there is a: • .001 percent difference in genome, your DNA would not match the crime scene/you are not the baby’s father. • 0.5 to 4 percent difference in genome, you may be a chimpanzee. • 50 percent difference in genome, you may be a banana.
Chimp/Human Y chromosomes differ by 30% in the MSY region - from Hughes, et al, 2010 -Chimp Y chromosome lacks 50% of the genes found on the human Y - The Y chromosomes are as different from each other as the human’s and the chicken’s!
How Genes Work • Genes are not blueprints; they are molecules. • These molecules have the ability to direct the assembly of proteins that build the body. • This genetic protein assembly can be turned on and off by the environment, or by other genes. • Any trait we see is a result of the complex interactions of many genes and countless other molecules.
Genetic Influences on Behavior • Both heredity and environment influence physical and behavioral traits. • Behavior genetics • The study of how the genotype and the environment of an organism influence its behavior A Difficult Child vs. An Easy Child Societal Attractiveness Parenting
Nature and nurture working togetherInteraction of Genes and Environment • Some traits, such as the overall design of our bodies, are set by genes. • Other traits, such as physical and mental abilities, develop in response to experience. How does the interaction of genes and environment work? • Genetic traits influence the social environment, which in turn affects behavior.
Genetic Influences on Behavior • Molecular genetics seeks to identify specific genes that influence behavior. • Molecular genetics • The sub-discipline in biology that studies the molecular structure and function of genes to determine how they influence behavior
Genetic Influences on Behavior • Controversies surround genetic explanations of certain sex and race differences. • Sex • The biological status of being female of male • Gender • The meaning that societies and individuals attach to being female and male • Does race tell us anything useful about how people differ genetically? • In 1972, Richard Lewontin performed a statistical analysis using 17 markers (including blood-group proteins). He found that the majority of genetic differences between humans (85.4 percent) were found within a population, 8.3 percent were found between populations within a race and 6.3 percent were found to differentiate races.
Nature, Nurture, and Human Diversity Gender Development • Gender Similarities and Differences • The Nature of Gender • The Nurture of Gender
Gender Development Based on genetic makeup, males and females are alike, since the majority of our inherited genes (45 chromosomes are unisex) are similar. Males and females differ biologically in body fat, muscle, height, onset of puberty, and life expectancy.
Gender Differences in Aggression Men express themselves and behave in more aggressive ways than do women. This aggression gender gap appears in many cultures and at various ages. In males, the nature of this aggression is physical.
Sexual Differentiation Sexual differentiation is not only biological, but also psychological and social. However, genes and hormones play a very important role in defining gender, especially in altering the brain and influencing gender differences as a result.
Gender Roles Our culture shapes our gender roles — expectations of how men and women are supposed to behave. Gender Identity — means how a person views himself or herself in terms of gender.
Gender Roles: Theories Social Learning Theory proposes that we learn gender behavior like any other behavior—reinforcement, punishment, and observation. Gender Schema Theory suggests that we learn a cultural “recipe” of how to be a male or a female, which influences our gender- based perceptions and behaviors. Tom Boys
