The Theory of Planned Behavior

Most important precondition for behavioral change

According to Bandura, self-efficacy

Applied nutrition intervention

In a recent study, TPB was utilized to encourage parents to pack more fruits, vegetables, and whole grains in sack lunches of preschool children. Behavioral constructs of TPB were used to develop intervention strategies.

Social influence

measured by evaluation of various social groups (most of my friends smoke, I feel ashamed of smoking in front of a group of friends who don't smoke)

behavioral intention

an indication of an individual's readiness to perform a given behavior. It is assumed to be an immediate antecedent of behavior. It is based on attitude toward the behavior, subjective norm, and perceived behavioral control, with each predictor weighted for its importance in relation to the behavior and population of interest

Behavioral belief

an individual's belief about consequences of a particular behavior. The concept is based on the subjective probability that the behavior will produce a given outcome

control beliefs

an individual's beliefs about the presence of factors that may facilitate or impede performance of the behavior. The concept of perceived behavioral control is conceptually related to self-efficacy

perceived behavioral control

an individual's perceived ease or difficulty of performing the particular behavior. It is assumed that perceived behavioral control is determined by the total set of accessible control beliefs

behavior

an individual's observable response in a given situation with respect to a given target. Ajzen said a behavior is a function of compatible intentions and perceptions of behavioral control in that perceived behavioral control is expected to moderate the effect of intention on behavior, such that a favorable intention produces the behavior only when perceived behavior control is strong

subjective norm

an individual's perception about the particular behavior, which is influenced by the judgment of significant others

normative beliefs

an individual's perception of social normative pressures or relevant others' beliefs that he or she should not perform such behavior

Attitude toward behavior

an individual's positive or negative evaluation of self-performance of the particular behavior. The concept is the degree to which performance of the behavior is positively or negatively valued. It is determined by the total set of accessible behavioral beliefs linking the behavior to various outcomes and other attributes.

Human behavior is guided by 3 kinds of consideration

Behavioral beliefs, normative beliefs, and control beliefs

BI

Behavioral intention

Strengths of the theory

-can cover people's non-volitional behavior which cannot be explained by TRA -an individual's behavioral intention cannot be the exclusive determinant of behavior is incomplete. By adding PBC, the TPB can explain the relationship between behavioral intention and actual behavior -includes social norm as a factor

Applications of TPB

-health studies: improve predictability of intention in various health-related fields such as condom use, leisure, exercise, and diet. -pro-social behaviors such as charitable giving -environmental psychology: generally, actions that are environmentally friendly carry a positive normative belief. (sustainable behaviors are widely promoted as positive behaviors) BUT even though there may be a behavioral intention to practice these behaviors, perceived BEHAVIORAL CONTROL can be hindered by constraints such as belief that one's behavior will not have any impact.

Limitations of the theory

-some scholars claim that the theory of planned behavior is based on cognitive processing and have criticized the theory on those grounds.

AB

Attitude toward behavior

TRA

Theory of Reasoned Action: An individual's decision to engage in a particular behavior is based on the outcomes the individual will come as a result of performing the behavior

W'

empirically derived weight/coefficient

e

evaluation of the outcome or attribute

"control beliefs"

gives rise to perceived behavioral control

PBC

perceived behavioral control

behavioral beliefs

produce favorable or unfavorable "attitude toward the behavior"

Outcome expectancy

refers to a person's estimation that a given behavior will lead to certain outcomes

"normative beliefs"

result in subjective norm

b

strength of each belief

c

strength of each control belief

SN

subjective norm

Self-Efficacy

the conviction that one can successfully execute the behavior required to produce the outcomes

m

the motivation to comply with the referent

p

the perceived power of the control factor

n

the strength of each normative belief

TPB

Attitude toward behavior, subjective norms, and perceived behavioral control together shape and individual's behavioral intentions and behaviors

AB, SN, and PBC combine to form

Behavioral Intention