Psychological Development

• Genes inherited from parents influence physical development, including blood type, eye and hair color, likelihood of developing physical diseases or disorders, brain and nervous system growth and maturation, brain chemistry and functioning, and onset of puberty
• Genes inherited from parents influence physical development


  Includes brain, nervous system, and hormone production, which in turn influence psychological development
• Heredity


  1. Transmission of characteristics from biological parents to offspring via genes at the time of conception

  2. Sperm cell fertilises the egg cell at conception, combining chromosomes from each parent to form a zygote with a unique combination of genes
• Complex psychological characteristics like intelligence and personality have a genetic component and are influenced by heredity
• Genes are believed to influence the onset of some psychological or 'mental health' disorders like schizophrenia, depression, and addictive drug use by affecting brain chemistry and functioning
• Having a biological parent with schizophrenia increases the likelihood of developing the disorder, but it doesn't guarantee inheritance
• Environmental factors


  Play an important role in shaping psychological development by encompassing all experiences, objects, and events throughout a lifetime
• Every experience a person has in their life has the potential to impact their psychological development, with some environmental factors exerting greater influence at specific life stages
• Genes


  Do not directly activate any mental process or behaviour
• Early psychologists debated the nature versus nurture concept, with some believing in hereditary (nature) and others in environmental (nurture) influences on development
• Environmental factors influencing psychological development

  • Having brothers and sisters
  • Upbringing
  • Friendship groups
  • Schooling
  • Job
  • Income level
  • Housing
  • Having a partner
  • Religion
  • Ethnic origins
  • Exposure to print or electronic media
  • Use of social media
  • Experiencing major stressful life events
  • Health
  • Other personal and sociocultural factors
• John B. Watson: 'Give me a dozen healthy infants, well-formed, and my own specified world to bring them up in and I'll guarantee to take any one at random and train him to become any type of specialist I might select - doctor, lawyer, artist, merchant-chief and, yes, even beggar-man and thief, regardless of his talents, penchants, tendencies, abilities, vocations, and race of his ancestors'
• Psychologists agree that individual development begins with the genetic instructions inherited at conception, providing the blueprint for psychological and physical characteristics
• Genes consist of DNA containing relevant information, and the expression of this information is influenced by numerous environmental factors
• Experiences that influence one person's development may not impact another's, showing the variability in the impact of environmental factors
• Those with a 'biological' perspective believed heredity primarily determined psychological development, with some suggesting that every aspect of psychological development was gene-determined
• All environmental factors can impact the kind of person we become and the psychological changes we experience during our lifetime
• Research evidence has shown that both hereditary and environmental factors interact to shape human development
• Behaviourists believed that with the right environment, individuals could achieve extraordinary feats regardless of their genetic make-up
• Psychologists who adopted a strict behaviourist perspective believed that the environment primarily determined what individuals would become
• Some believed that every aspect of psychological development was determined by genes, including social skills, musical ability, personality, and intelligence
• Psychologists and scientists aim to establish how much heredity and environment contribute to the development of specific psychological characteristics
• Hereditary and environmental factors interact in shaping psychological development and influencing behavior and mental processes
• Behaviourists ignored the influence of genes in development and believed that all thoughts, feelings, and behavior could be explained by a person's learning throughout their life
• Psychologists now consider the nature versus nurture debate to be resolved and focus on understanding how hereditary and environmental factors interact in influencing thoughts, feelings, and behavior
• Behaviourists believed that differences between people were the result of differing environmental experiences
• Psychologists debated for many years whether heredity or environment determined human development, known as the nature versus nurture debate
• Some psychologists believed heredity had little to do with the development of psychological characteristics
• Current technology is not able to detect exactly how much of a particular psychological characteristic or behavior may be attributable to either heredity or environment
• Individuals with a genetic predisposition for schizophrenia may not actually develop schizophrenia until they experience a major stressful life event, such as the loss of a loved one
• We are all active players in the process of psychological development, starting at birth
• The two-hit model of schizophrenia illustrates the interaction between hereditary and environmental factors in the onset of schizophrenia
• Both nature and nurture contribute to psychological development, and both are essential to all aspects of psychological development
• All the abilities and potentials with which we are born will influence our environmental experience, which may then modify our development in significant ways
• As infants, we are not passive recipients of the environment, like a blank sheet of paper on which the environment writes
• A person who loses a loved one and does not have a genetic predisposition for schizophrenia is less likely to develop schizophrenia
• Psychologists do not know the specific environmental factors required to interact with genes to produce a particular psychological characteristic or behavior
• Career choice primarily involves psychological processes but is also greatly influenced by social factors, possibly biological factors too if the individual has an inherited disability that limits career choices
• Biological factors


  • Physiologically based or determined influences, genes we inherit, age, sex, race, brain chemistry, brain and nervous system functioning, hormonal activities, physical injury, illness or disease, sleep patterns, body responses to medications, bodily responses to stress
• Social factors

  • Influences from the external social environment, interpersonal relationships, support from family, friends, social media use, schooling, employment history, economic circumstances, housing situation, access to health care, exposure to stressors, cultural influences