Glossary of Terms: Early Child Development

Terms and Definitions compiled by Karen Brown and courtesy of Ann Masten, Ordinary Magic; Aisha Yousafzai; for Neuroscience; Lisa Guernsey; Rana Dajani; Harvard University Center On The Developing Child; National Center for Biotechnology Information/National Institutes of Health; Wiley Online Dictionary; Linda Richter/World Health Organization; National Academies Press; UNICEF/2016 Lancet ECD report; Wikipedia.

Adverse Childhood Experiences (ACEs): potentially traumatic events or circumstances that can have negative, lasting effects on adult health and wellbeing. These experiences range from physical, emotional, or sexual abuse to parental divorce or the incarceration of a parent or guardian.

Allostatic Load: the physiological “wear and tear on the body" that results from repeated or chronic stress. It is used to describe how frequent activation of the body's stress response systems, which are essential for managing acute threats, can in fact damage the body in the long run.

Attachment: An emotional bond between infant and one or more adults. The infant will approach these individuals in times of distress, particularly during the phase of infant development when the presence of strangers induces anxiety. In addition, the infant is distressed if separated from attachment figures.

Autonomic nervous system (ANS): a division of the nervous system that acts largely unconsciously and regulates bodily functions such as heart rate, respiratory rate, digestion, and the response of the eye’s pupil’s to light. This system is a primary mechanism for controlling the fight-or-flight response.

Contingent responsiveness (“serve and return”)—adult behavior that occurs immediately after a child’s behavior and that is related to the child’s focus of attention, such as a parent smiling back at a child.

Coping: efforts to regulate the self or the environment under stress, a key concept in the study of resilience. Coping includes strategies such as problem solving, seeking support, minimizing pain, self-encouragement and self-distraction

Correlation vs. Causality – Basic research terms that distinguish between an effect that occurs along with a particular environmental condition (correlation) but not necessarily as a result of that condition (causality).   

Cortisol is a steroid hormone produced by the cortex of the adrenal gland. Cortisol is often thought of as a “stress hormone”, but it is also secreted under low stress conditions and plays important roles in everyday functioning, rising and falling during our sleep-wake cycle where it regulates metabolism and acutely enhances our immune defenses. When we are stressed we produce high levels of this hormone. When secreted at high levels under stress, it increases the sensitivity of brain circuits involved in processing and retaining information about threat, which may help us avoid future dangerous situations. However, chronic or frequent elevations in cortisol can result in changes in brain architecture resulting in impairments in cognitive functioning, poor brain development and wear-and-tear on many organs and tissues of the body.  

Critical periods (similar to, but not exactly the same as, sensitive periods): a time during an organism’s life span when it is most sensitive to environmental influences or stimulation than at other times during its life. If, for some reason, the organism does not receive the appropriate stimulus during this "critical period" to learn a given skill or trait, it may be difficult, ultimately less successful, or even impossible, to develop some functions later in life.

Cumulative risk: Combined effects of multiple or repeated risk factors; accumulating effects of ongoing adversity

Cybernetic theory: The study of regulation and control in systems by feedback, used to explain aspects of the purposeful behavior of human beings. Norbert Wiener, an American math- ematician during World War II, originated the theory to describe and design mechanisms that rely on feedback to change direction.

Developmental psychology: The field of psychology concerned with the processes of change across the lifespan. Developmental psychologists focus predominantly on childhood development, and developmental psychology has become synonymous with child psychology.

Early Childhood Development (ECD) - Early childhood development is often understood as a process that begins with conception and continues through age 8.  While each child is unique, general patterns of development are similar. During this critical period, children develop motor, cognitive, linguistic and socio-emotional skills and the foundational architecture of the brain is laid.  All development throughout life builds on the foundational capacities established in early childhood. ECD has also been defined as a comprehensive approach to policies and programs for children and their parents, caregivers and communities from the prenatal period through children’s entry into school.

Epigenetics: the study of changes in organisms caused by modification of gene expression rather than alteration of the genetic code itself. This fast-growing field of study looks at the role of experience, environment, nutrition, and other external factors in changing gene expression – including from one generation to another.

Executive function & self-regulation skills: the mental processes that enable people to plan, focus attention, remember instructions, and juggle multiple tasks successfully. These skills are crucial for learning and development. They also enable positive behavior and allow us to make healthy choices for ourselves and our families. Executive function and self-regulation skills depend on three types of brain function: working memory, mental flexibility, and self-control. 

Gene-environment interaction: how environmental influences can actually effect whether and how genes are expressed. Despite the belief that genes are “set in stone,” research shows that early experiences can determine how genes are turned on and off and even whether some are expressed at all. Therefore, the experiences children have early in life—and the environments in which they have them—shape their developing brain architecture and strongly affect whether they grow up to be healthy, productive members of society.

HPA Axis: a term used to represent the interaction between the hypothalamus, pituitary gland, and adrenal glands. Scientists believe it plays an important role in the stress response.  Maltreated children are thought to have a greater risk of HPA dysfunction.

Intervention: Attempt to influence or change the course of events by providing care or information or otherwise manipulating a situation.

Joint media engagement: When two people (such as a parent and a child) watch or play with digital media together and engage each other with questions or dialogue while doing so.

Neuroplasticity: the brain's ability to reorganize itself by forming new neural connections throughout life. Neuroplasticity allows the neurons (nerve cells) in the brain to compensate for injury and disease and to adjust their activities in response to new situations or to changes in their environment.

Nurturing care –  A stable environment that is sensitive to children’s health and nutritional needs, with protection from threats, opportunities for early learning, and interactions that are responsive, emotionally supportive, and developmentally stimulating.

Positive Stress Response: a normal and essential part of healthy development, characterized by brief increases in heart rate and mild elevations in hormone levels. Some situations that might trigger a positive stress response are the first day with a new caregiver or receiving an injected immunization.

Post-traumatic stress: Biological and psychological reactions to severe adversity experiences, including anxiety, fear, jumpiness, nightmares, feeling like you are reliving the trauma, emotional numbing, intrusive memories of the traumatic experience

Post-traumatic stress disorder, or PTSD: A disorder that can arise following exposure to traumatic experiences when post-traumatic symptoms persist longer than usual; usually defined by persisting symptoms of reliving the experience (e.g., flashbacks or intrusive memories), avoiding situations that bring the traumatic experience to mind, frightening thoughts, feeling constantly on guard or hyperaroused (e.g., jumpy, startle easily); and feeling numb or detached; children may act out the scary event in their play, show regression (e.g., bedwetting), or be very clingy.

Promotive factor: A general predictor of good adaptation or desired outcomes; sometimes called an asset or resource.

Protective factor: A moderator of risk or adversity that has more effect or extra effects when risk or adversity is high than it does when risk is low, such that the individual does better than would be expected for that level of risk

Psychosocial Deprivation: The absence of appropriate stimuli in the physical or social environment which are necessary for the emotional, social, and intellectual development of the individual.

Psychosocial Stimulation: providing a child physical stimulation through sensory input (e.g. visual, auditory, tactile) as well as emotional stimulation through an affectionate caregiver-child bond. The formation of this bond at the beginning of life sets the state for cognitive, emotional, and social development later in life. Feeding and other care practices provide opportunities for psychosocial stimulation and help establish a positive attachment between caregiver and child.

Resilience: Capacity (potential or manifested) of a person (or any dynamic system) to adapt successfully to disturbances (adversities and risks) that threaten the function, survival, or development of the individual (or the system); positive adaptation or development in the context of significant adversity exposure. The definition of resilience is up for wide interpretation, but most agree it does not refer to a static personality trait or attribute, but rather a process or construct that combines exposure to adversity with response and outcome.

Risk factor: Indicator of risk for a specified negative or undesirable outcome in a group of people

Scaffolding: A concept derived from Lev Vygotsky’s theory of mediated learning, scaffolding is the process by which someone organizes an event that is unfamiliar or beyond a learner’s ability in order to assist the learner in carry out that event.

Secure attachment: A child who is securely attached actively explores the environment in the presence of the caregiver, is visibly upset by separation, and greets the caregiver warmly when they are reunited.

Sensitive Periods (similar to, but not exactly the same as, critical periods): Windows of time early in life when the brain is actively shaped by environmental input – for both good and bad. In recent years, scientists are discovering pathways in animal models through which these windows might be re-opened in adults, thus re-awakening a brain’s youth-like plasticity. Such research has implications for brain injury repair, sensory recovery, and neurodevelopmental disorder treatment – as well as social and educational policy.

Separation effects: When a child has formed an attachment, she will display any of a range of distress behaviors when separated from the attachment figure, including protest, fearfulness, and despair.

Stress: Effects of disturbances in an individual or system that disrupt adaptive functions; response of a dynamic system to challenges or demands; biological and psychological processes associated with responses of individuals to challenges 

Stress buffering refers to the concept of supportive adult relationships that lessen the impact of a young child’s response system when exposed to stress. This interaction fosters a return to baseline of physiological responses such as increased heart rate, blood pressure, and the release of stress hormones such as cortisol.

Stress inoculation: The process by which milder or manageable experiences of challenge improve the response of a person to future stressful experiences; when stress exposure or challenges strengthen or prepare a system for better future adaptation.

Stunting - low height-for-age, caused by long-term insufficient nutrient intake and/or frequent infections. The prevalence of stunting in a population measures how many children are not growing well due to chronically poor nutrient intake. Stunted children are at risk of impaired brain development, lower IQ, weakened immune systems and serious health complications like diabetes and cancer later in life.

Synapse – the contact point where one neuron communicates with another, between the dendrite of one cell and axon of another. The synapse allows one neuron to pass an electrical or chemical signal to another.

Synaptic pruning: the process of synapse elimination in the brain that occurs (mostly) between early childhood and the onset of puberty in many mammals, including humans. Pruning is influenced by environmental factors and is widely thought to represent learning. After adolescence, the volume of the synaptic connections decreases again due to synaptic pruning.

Telomere: the end section of a chromosome (picture the plastic piece at the end of a shoelace) that appears to protect the integrity of DNA and keep it stable through replication. Research suggests that stress shortens the length of telomeres, hastening cell death and negatively affecting an individual’s health and longevity.

Tolerable stress response (as compared to positive stress response): activation of the body’s alert systems as a result of more severe, longer-lasting difficulties such as the loss of a loved one, a natural disaster, or a frightening injury. If the activation is time-limited and buffered by relationships with adults who help the child adapt, the brain and other organs recover from what might otherwise be damaging effects.

Toxic stress response (as compared to positive and tolerable stress response): reaction to strong, frequent, and/or prolonged adversity—such as physical or emotional abuse, chronic neglect, caregiver substance abuse or mental illness, exposure to violence, and/or the accumulated burdens of family economic hardship—without adequate adult support. This kind of prolonged activation of the stress response systems can disrupt the development of brain architecture and other organ systems, and increase the risk for stress-related disease and cognitive impairment, well into the adult years.

Vulnerability: The susceptibility or sensitivity of individuals or systems to harm from a particular situation, threat, or risk factor; a moderator of response to adversity or risk that results in higher than typical negative effects