# What is a latent variable?

##### 2 Answers

A latent variable is a variable which is not directly observable and is

assumed to affect the response variables (manifest variables)...

For more on Latent Variables read the explanation...

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#### Explanation:

Consider the following sentence: “Einstein would not have been

able to come up with his e mc2 had he not possessed such an

extraordinary intelligence.” What does this sentence express? It

relates observable behavior (Einstein’s writing e mc2) to an

unobservable attribute (his extraordinary intelligence), and it does

so by assigning to the unobservable attribute a causal role in

bringing about Einstein’s behavior. In psychology, there are many

constructs that play this type of role in theories of human behavior;

examples are constructs like extraversion, spatial ability, selfefficacy,

and attitudes. Such variables are usually referred to as

latent variables. It is common to investigate the structure and

effect of unobservables like intelligence through the analysis of

interindividual differences data by statistically relating covariation

between observed variables to latent variables. This is done, for

example, in the widely used factor model. The idea is that although the fit of a latent variable model to the data may not prove the existence of causally operating latent variables, the model does formulate this as a hypothesis; consequently, the fit of such models can be adduced as evidence supporting this hypothesis. Finally, it is often suggested that the type of causal relation tested in latent

variable modeling is similar to the relation between Einstein’s

intelligence and behavior in the above example; that is, the latent

variable exerts influence at the level of the individual.

Given the intuitive appeal of explaining a wide range of behaviors

by invoking a limited number of latent variables, it is not surprising that latent variables analysis has become a popular technique in post behaviorist psychology. The conceptual framework

of latent variables analysis, however, is older than cognitive

psychology and originates with the work of Spearman (1904), who

developed factor analytic models for continuous variables in the

context of intelligence testing. The basic statistical idea of latent

variables analysis is simple. If a latent variable underlies a number

of observed variables, then conditionalizing on that latent variable

will render the observed variables statistically independent. This is

known as the principle of local independence. The problem of

latent variables analysis is to find a set of latent variables that

satisfies this condition for a given set of observed variables.

Latent variables are variables that are not directly observed but are rather inferred, through a mathematical model, from other variables that are observed.