Social Impact Theory


  • This theory was developed by Bibb Latane in 1981
  • His theory underlies Milgrams theory as well as expanding on Social Identity Theory.
  • Latane argued that every person is subject to influence from social force.
  • He theorised three rules that are at work:
  • 1. Social Force - this is a kind of pressure that through persuasion, threat, humour, embarrassment etc, if it works it becomes known as social impact. Social force fetures three aspects that effects the impact:
  • 1. Strength - this is the amount of power you believe a person has over you, this may be affected by context, for example if a person has a higher rank in an organisation or has title or job that we are supposed to expect like police people.
  • 2. Immediacy - this is how recent the influence and close the person is to you when the influence occurs whether it is an order from your boss a minute ago while they stand over you or an email a week ago.
  • 3. Numbers - the more people applying influence the higher the chance it becoming social impact.
  • This can be seen in Milgrams study varations 7 and 13
  • Bibb also came up with an equation to work out the social impact in any situation, this is i = f (SIN) where S, I and N are Strength, Immediacy and Numbers.
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Outline Cont.

  • 2. Psychological Law - this is the rule that incresing the amount of figures influencing a person does not neccesirily increase the likely hood of the influence becoming impact. For example being watched by one person may make you feel awkward and result in influence becoming impact but adding another person does not double the awkwardness and likelihood of influence becoming impact. Adding more authority figures can increse the pressure, not a large amount and actually adding to many figures can lead to a complete shut down of obedience.
  • 3. Divisions of Impact - this is the rule that the more people influence is directed at the more the power of the influence is diffused, if influence is directed at one person then its power and the likelihood of influence becoming impact is increased, but if it is directed alarge group then there is higher 'diffusion of responsibility' and so they feel less personal responsibility. 
  • This can be seen in Milgrams variation where obedience decreased when the pps were paired with a rebellious stooge.

  • Latene had an equation for this as well: i = f (1/SIN) 
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Research into the Theory

  • Latane (1981) - gave examples of the theory in action, for example Billy Graham was an well known and contreversial evangalist preacher that during his sermons and speaches woud attempt to convert people to his way of thinking and particular brand of Christianity. Latane found that when he preached in front of small groups there were more people interested in converting compared to larger audiences, this demonstrates well the divisions of impacts and the diffusion of personal responsibility.
  • Sedikides & Jackson (1990) - carried out an experiment at a zoo where a group of people where told by a confederate not to lean on the railings of a bird house, they were then observed to see if they complied. The independant varible they manipulated was how the confederate was dressed. They found out that the more casually they were dressed the less the people complied. This shows varying social force as the strength changes with how the person is dressed. As time went by less people followed the instructions showing the effect immedacy as a varible. The divisions of impact where also demonstrated by the fact larger groups where less likely to comply than when a few where told to not lean.  
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Evaluating Social Impact Theory Strengths

  • Credibility 
  • There is a large body of research that continues to back up the theory as well utilizing many seemingly unconnected studies that actually build up various components of the theory like the diffusion of responsibility study conducted by Latane & Darley (1968), Tajfel's intergroup discrimination one carried out in 1970 and evens Milgram's 1963 study.
  • There have been modern additions to the theory including the development of the Dynamic Social Impact Theory by Latene (1996) again. This one explores how majorities and minorities influence each other for example why some people change their views becaused of the groups they are in and why others keep the same views.
  • Differences
  • In Milgram's Agency theory it is suggested that we have evolved to be obedient to anyone we have determined an authority figure this is quite a simplistic view and there is not much evidence for this. SIT develops many aspects of his theory including the strength aspect as well as the proximity variable that can affect the effectiveness of an order and whether a person complies.
  •  Applications
  • Because of the presence of a mathematical formula that looks at the amount of people the immediacy etc., this means the police can calculate the likelihood of a riot occuring. The theory suggests that people will do anything if social force is applied to small groups and people should be stopped to getting into larger groups. This is applied by repressive governments that stop people using the media and gathering for public meetings. Adverts use the fact that people respond better to orders immediately applied by playing ads several times


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Evaluating Social Impact Theory Weaknesses

  • Objections
  • The theory seems to ignore the person receiving the orders and their potential individual differences and instead just focuses on the person giving the orders. This does not account for the fact that certain personalities may be more susceptible to being compliant and visa versa.
  • It also treats people as passive and says that anyone will follow orders if enough social force is applied and ignores those that follow some and subvert others like in the Oskar Schindler case this may not be the truth.
  • Differences
  • On the other hand agency theory also takes into account of the prestige of the surroundings as a variable (Variation #10) which is hard to express as a mathematical equation as Latene did before. He also looked at ‘moral strain’ and why people refused which is not featured in SIT.

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