Elaboration likelihood model

Petty Cacioppo’s (1981) ELM suggests that there are two ways a message can persuade someone to change their mind or behaviour.
ELM Processes:
- central route
- peripheral route
Influences:
- other factors
- individual differences

Processes
Central route:
Someone is persuaded by the message itself after they have fully processed the content in detail.
This could be because they are interested in that topic or are personally motivated by the message.
This is called high elaboration because the message's content has been assessed at the highest level.
Peripheral route:
Someone is persuaded by other factors, which could be celebrities or a certain design.
The content isn’t processed properly, this could be due to not having any interest, time or ability.
This is called Low elaboration as the evaluation of the message is minimal.

Influences
An individual can be persuaded either by the peripheral or the central route, however there are factors that determine which route is used.
Factors:
- interest in the topic
- relevance of the topic
- attractiveness of the presenter
- need for cognition to understand

Individual differences
Individuals naturally differ in their ability and desire to process a message centrally.
People with a high need for cognition (NFC) are motivated to think about a lot of issues - they enjoy analysing arguments.
Therefore, people with an nfc are easily persuaded via the central route, whilst others may be persuaded by the peripheral route.

Aim: to understand if high engagement takes the central route and low engagement takes the peripheral route.
Findings: when personal involvement was high, the main factor was the quality of the message (strong message = highly persuasive). Expertise had no effect.

Strengths:
- highly influential in the persuasion research
- this study had genuine value and aims improve our understanding of our world.
- the ELM can help us make health messages more persuasive

Weaknesses:
- only used uni students
- unrepresentative because it is difficult to generalise beyond the sample
- the ELM doesn't explain how it affects behaviour, meaning it’s hard to use to predict actual behaviour changes.