Developmental (lifespan) psychology

Developmental psychology is interested in identifying and describing processes that produce cognitive, intellectual, perceptual, social, personality and emotional changes across the lifespan. In other words, the things that change as we get older, how they change, and why those changes happen. This subdiscipline was originally concerned with development from birth to adolescence, due to the rapid and extensive changes that take place within this period. However, the field has evolved into a lifespan perspective; acknowledging that change continues into adulthood.

Some of the key concepts, issues and debates within lifespan psychology include:

• Developmental theory: Including Freud's and Erikson's psychodynamic stage models, Piaget's cognitive theory and Bowlby's ethological approach.
• Language and communication: This involves preverbal communication, how children acquire language and grammar.
• Emotional development and attachment: Including emotional individuality (temperament), emotional regulation, understanding and recognising emotions in others, the quality of the emotional bond between caregiver and infant, which can be characterised as secure (adaptive) or insecure (maladaptive) attachment.
• Atypical development: The aetiology of developmental differences and disorders (e.g., ADHD, autism, enuresis, speech problems), and interventions to improve outcomes.
• Ageing and dying: This includes considerations around life expectancy, changes to the brain, health problems, end-of-life decisions and stages of dying.

Methodologies and applications

A range of approaches can be used to investigate development across the lifespan, including naturalistic observations, laboratory experiments and questionnaires. However, it is important to consider the age of participants, because infants and young children cannot be studied using the same methods as older children or adults, due to differences in their ability to comprehend and co-operate. Ethical concerns around the issue of informed consent also pose a challenge for developmental psychologists because of the reduced ability of infants and children to convey their understanding of risk, their willingness to participate, and to indicate when they want to withdraw from research.

Developmental psychologists usually focus on a specific age range and topic of development. Some of the main applications include working with children and young people in clinical or educational settings to assess, evaluate and treat intellectual and developmental disorders, such as autism, and with older adults in healthcare settings, supporting the day-to-day living, health and well-being of those with conditions related to ageing, such as dementia.

Activity: Developmental psychology experiments

In this activity you can learn about how research is conducted in developmental psychology. While watching these videos, consider how concepts, issues and debates discussed in the previous section are being demonstrated by these different tests and videos.

This activity should take no longer than 30 minutes; you do not need to submit any work.

Experiment 1: The Sally-Ann Test is a False Belief Task, which is commonly administered to determine if a child has developed 'Theory of Mind' – this is the idea that people can have different thoughts and feelings from one another.

You can see this test being administered in this 5-minute video:

Experiment 2: The Strange Situation test was developed by Mary Ainsworth in 1969, to assess the quality of a child's attachment to their caregiver.

You can watch this experiment being conducted in this 5-minute video:

How do babies learn language? You can watch this 10-minute Ted Talk by Dr. Patricia Kuhl, which considers the critical period for language acquisition:

Suggested Wider Reading

If you would like to learn more about lifespan psychology, you can read the following text that is available through your online reading list:

• Santrock, J. W. (2021). Life-span development (18th ed.). McGraw-Hill.

You may also wish to investigate The Journal of Applied Developmental Psychology.