a set of steps, or a cycle of procedures that guide scientific investigation progressing (usually) from prior theory to hypotheses to observations to conclusions (and back to theory). The scientific method guides the pursuit of knowledge in science, allowing us to verify, modify and sometimes reject the theories used to explain whatever we may study :including, of course, psychology in general, and human development in particular.
an organized, logical, rational explanation of facts, observations, beliefs, assumptions and expectations about something one can scientifically study (human development, for example).
a prediction of what will happen when one makes a scientific observation that is designed to verify (or falsify) a theory. An educated guess based in a theory.
any one of the many forms of data gathering that may be used to verify (or falsify) a scientific theory or prediction.
a specific kind of scientific observation in which changes in one factor or force (called the independent variable) are made in order to see if there is a corresponding, predictable change in an outcome (or dependent) variable. This sort of research is the best at revealing cause and effect relationships.
a means of gathering data from subjects (often with questionnaires or tests) by asking them to self-report on their characteristics. Involves no experimental manipulation, and so does not provide direct observation of cause and effect relationships. Commonly called a correlational method of research.
a method of gathering data unobtrusively, observing subjects without interfering in their behavior in any way. Commonly called a correlational method of research.
a statistical relationship between variables that can have values from - 1 to + 1. A correlation indicates the degree to which one variable can be predicted from the level of another, but does not indicate causation.
the result of examining data from scientific observations, relating them back to the theory used to predict or explain them.
increase in number, size, ability or complexity.
growth that proceeds according to a particular species’ genetic plan. Pattern of growth up to and including optimum number, size, ability or complexity.
development after passing the peak of optimum number, size, ability or complexity.
a period of rapid decline in the few years, months, or weeks prior to death, usually only occurring after extended, advanced ageing.
the influence of inbred, inborn forces that might produce growth, maturation, ageing, behavior, or traits. Taken mainly to refer to the influence of one’s genes
the influence of factors outside an organism that might affect growth, maturation, ageing, behavior, traits, states, etc. Taken to mean the social, educational, physical and/or family environment that surrounds an individual.
the overall collection of expressed traits actually possessed by an organism.
the division of body cells, resulting in cells that contain a complete set of chromosomes.
the cell division process that forms gametes, resulting in cells that each contain half a set of the parent’s chromosomes.
The union of a sperm and an ovum, forming a zygote.
the embedding of a blastocyst into the lining of the uterus. This process is necessary for continued gestation to take place in the womb (and in humans is successful only about half the time).
The progressive maturation of an organism from a zygote to an infant, which, when successful, ends in the birth of that organism.
the process whereby body cell reproduction (through mitosis) results in the formation of new types of tissues. This process causes the formation of all the body’s organs and structures while in the womb.
the growth of nerve fibers into tissues such as muscles, glands and other organs.
the branching of neurons’ dendrites, which are responsible for receiving most neural messages.
the fatty insulating material that surrounds the axons of neurons, and which speeds up and specializes the transmission of neural signals.
the progressive growth of myelin into areas of the brain, occurring over the course of its maturation.
the increase over time in the specialization of the two halves (left and right hemispheres) of the cerebrum.
the capacity to make choices, to be the cause of one’s own behavior, to act on one’s intentions (even going against the direction of other influences).
the principle of cause and effect. The core principle behind all scientific explanations of objects and organisms. Takes the form of simple, linear determination, and can be part of interdetermination and multidetermination.
the result of forces or factors that came before a cause; an outcome.
emotional states, traits, abilities and experiences of the individual.
the principle that says that increases in number, size, ability and complexity ultimately bring about increased organization, and that this produces new levels of function.
the principle of growth that says that various bodily or psychological systems grow more interrelated over time.
the principle of growth that says that various bodily or psychological systems grow more independent of each other’s influence over time.
the idea that growth proceeds in a slow, steady accumulation of structures, functions or abilities. Stages, if they exist at all, are not clearly recognizable.
the idea that growth proceeds in fits and starts, bursts of change, followed by periods of little change (stability). Organized, predictable discontinuous change allows us to describe development in clearly recognizable stages.
changes that bring about new levels or types of ability, function, structure and complexity.
changes in the number or size of an organism’s structures, functions or abilities.
causing growth or development, either from within or from outside the organism.
growth or development caused from within the organism. Example: genetically driven growth of tissues making up the body’s organs.
growth or development caused by forces or factors outside of the organism. Example: nutrition in one’s diet that promotes (or limits) maturation.
the factors in growth and maturation that cause early development to prefigure (predetermine the form of) later development.
the study of how the environment interacts with genes at a chemical level, affecting their expression in ways that are potentially transmissible across generations.
thinking, knowing, remembering, and reasoning; includes believing, imagining, perceiving, predicting, expecting, planning, etc. The use of the mind to process information and/or solve problems.
a marker of normal development or growth. Reaching particular milestones at normal ages allows us to recognize a normal pattern of growth and maturation.
a certain specific time frame within which key developmental events must happen properly if later development is to proceed normally. Impairments in growth occurring during critical periods generally can not be overcome later.
a less-than-critical period during which growth still needs to proceed normally for later development to turn out well, but in which there is less sensitivity to the environment or later effects of impaired development than there would be in a critical period as described above. A ‘softer’ version of a critical period, so to speak.
an uncertain time frame, one that has gradual or uncertain onset and ending.
growth from the head downward; head-to- tail growth.
growth from the trunk outward; near-to-far growth.
The idea of there being a causal force (an agent) that effects the changes in an organisms behavior, either over time or in a given circumstance.
The view (from the philosophy behind 19th century biology) that living organisms do what they do because of the power of their internal life force. In short, vitalists would locate the causes of development in the mere fact of being alive, and in seeking to preserve life.
The view that living organisms operate almost like machines; that is they follow the laws of physics in all ways and do what they do because of the physically explainable forces of physics, physiology, chemistry, etc.