Introduction to Lifespan Development

• Lifespan development is a multidisciplinary study of how individuals change physically, cognitively, and psychosocially from conception until death.
• Biology, psychology, sociology, education, and history are all involved.
• Understanding it is crucial as it gives insight into individuals, human nature and effects of life events.
• Frameworks for understanding the reasons and methods behind people's changes as they age can be found in lifespan development theories.

Stages of Lifespan Development

• Rapid physical growth and the emergence of fundamental bodily structures characterize prenatal development from conception to birth.
• Major developments in motor, sensory, and cognitive abilities characterize infancy and toddlerhood, from birth to age three.
• Early childhood, from ages 3 to 6, is distinguished by symbolic thought, language development, and increased social interaction.
• Middle childhood, from ages 6 to 12, is distinguished by the growth of peer relationships, academic abilities, and a sense of competence.
• From ages 12 to 18, adolescence is a period of increased independence, identity formation, and puberty.
• Early adulthood, from ages 18 to 40, is a time of creating intimate relationships, starting families, and establishing careers.
• Middle adulthood, from ages 40 to 65, is distinguished by family duties, career consolidation, and a consciousness of aging.
• Late adulthood, from age 65 and beyond, entails coping with failing health, retirement, and reflecting on accomplishments in life.

Key Issues in Lifespan Development

• Nature vs. Nurture is an ongoing discussion about the relative effects of environmental variables (nurture) and genetic inheritance (nature) on development.
• Continuity vs. Discontinuity examines whether development happens in discrete stages or is a gradual, continuous process.
• Stability vs. Change examines the aspects of personality and behavior that alter throughout life and those that remain consistent.

Research Methods in Lifespan Development

• Longitudinal Studies: Observe changes directly by following the same people over an extended period.
• Cross-Sectional Studies: Identify age-related changes by comparing different age groups at one time.
• Sequential Studies: Study several age groups over time to combine cross-sectional and longitudinal methodologies.

Infant Development

• Infant development spans from birth to about age two.
• It entails significant physical, cognitive, and socio-emotional changes that set the stage for future development.
• Language, cognition, socio-emotional development, perception, and motor skills are key components of infant development.

Physical Development in Infancy

• Height and Weight: During the first year, babies grow quickly in height and weight, often gaining three times their birth weight.
• Brain Development: The brain undergoes considerable development, marked by a sharp rise in synaptic linkages and neurons.
• Motor Skills: Infants acquire gross motor abilities (e.g., walking, crawling) and fine motor skills (e.g., reaching, grasping).
• Reflexes: Survival is aided by reflexes that newborns have at birth (e.g., rooting, sucking).
• Sensory Development: Infants' sensory skills grow quickly.
• Vision: By the end of the first year, vision develops from hazy at birth to almost adult levels.
• Hearing: Infants are born with well-developed hearing and can distinguish between various sounds.
• Taste and Smell: Preferences for sweet flavors exist, and taste and smell are also present from birth.

Cognitive Development in Infancy

• Piaget's Sensorimotor Stage: Infants learn through their physical actions and senses.
• Object Permanence: Usually develops around eight months, it is the awareness that things still exist even when they are not visible.
• Cognitive development includes the expansion of mental processes like problem-solving, memory, and attention.
• Attention: Infants' attention spans lengthen over time, enabling them to concentrate on stimuli for longer durations.
• Memory: Infants' capacity to remember gets better, which allows them to recall events and recognize commonplace জিনিস and افراد(People).
• Categorization: Infants start to arrange জিনিস into groups according to characteristics like size and shape.
• Imitation: An important mechanism for learning is when newborns mimic the actions of others.

Language Development in Infancy

• Prelinguistic Communication: Babies express themselves through coos, cries, and babbles.
• First Words: Usually, infants speak their first words around the age of one.
• Vocabulary Growth: During the second year, vocabulary increases quickly, and toddlers pick up new words every week.
• Telegraphic Speech: Toddlers start combining terms to form simple two-word sentences.

Socio-Emotional Development in Infancy

• Attachment: Babies establish deep emotional ties with their closest caregivers.
• Attachment Styles: Disorganized, resistant, avoidant, and secure attachment patterns have been found.
• Temperament: Infants have unique behavioral patterns, or temperaments, that affect how they engage with the world.
• Emotional Expression: Joy, grief, rage, and terror are just a few of the feelings that babies show.
• Social Referencing: When unsure of how to react in unfamiliar settings, babies turn to their caregivers for advice.
• Self-Awareness: Babies start to see themselves in mirrors and develop a sense of self.

Factors Influencing Infant Development

• Genetics: Genetic variables have an impact on cognitive and physical development.
• Nutrition: Healthy growth and development require proper nourishment.
• Environment: An encouraging and stimulating environment supports optimal development.
• Parental Caregiving: Sensitive and responsive caregiving fosters secure attachment and socio-emotional development.
• Culture: Cultural norms have an impact on infant care and development.
• Socioeconomic Status: Access to resources and opportunities that impact development is impacted by socioeconomic status.
• Early Experiences: Early traumas or stressors can have long-lasting effects on development.

Measurement of Infant Development

• Bayley Scales of Infant and Toddler Development: A standardized test used to assess cognitive, language, motor, social-emotional, and adaptive behavior in infants and toddlers
• Ages and Stages Questionnaire (ASQ): A questionnaire completed by a parent to screen young kids and infants for developmental delays.
• Observation: Observing newborns' behavior in controlled or naturalistic settings is also a technique to evaluate development.

Overview of lifespan development, covering physical, cognitive, and psychosocial changes from conception to death. It integrates biology, psychology, and sociology. Understanding this field provides insights into human nature and the impact of life events.