A
Diffusion/Contagion Model of Interracial Hostility[1]
Although we have devoted most of our efforts this semester to empirical approaches, it may help us think about how political science can influence minority politics, and how public policy can affect interracial hostility, if we explore a rational model of social behavior as a starting point. We will begin with some basic assumptions and a description of the model, which we might later wish to modify.
Assumptions: A person is either hostile toward members of another race or nonhostile. Once he/she becomes hostile, he/she stays hostile. Hostility spreads as a response to the expression of hostility (i.e., a black person becomes hostile toward white people as a result of encountering interracial hostility against himself/herself, and vice-versa).
Model: These assumptions allow us to create the following models:
and
Where M is the total number of blacks and m is the number of blacks who are hostile toward whites. N is the total number of whites and n is the number of whites hostile toward blacks. a is some measure of interracial communication (which will be described more fully below).
If we suppose that there is a society (community, workplace, etc.) of 10 black people and 40 white people, and that interracial communication is the same for both groups (a1 = a2 =0.02) and that there is initially 1 hostile black person and 1 hostile white person, then this is what happens to hostility over time:
t=5
In other words, after 5 time periods there are 3.3 hostile blacks and 7.0 hostile whites. After 10 time periods there are 8.4 hostile blacks and 21.3 hostile whites. Notice that in the early time periods the number of hostile whites increases more rapidly than the number of hostile blacks, but the proportion of hostile blacks increases more rapidly than the proportion of hostile whites.
Analysis: If we are interested in reducing interracial hostility, and if this model is accurate, what can we do? The behavior of the model depends on the values of a1 and a2. But what do each of these really measure? a1 is a measure of three things:
1. The opportunities hostile whites have to show hostility toward blacks (contact).
2. The extent to which those opportunities are used to express hostility (transmission).
3. The extent to which the expression of white hostility toward a black person produces a feeling of hostility in the black person (acceptance).
Similarly, a2 is a measure of three things:
4. The opportunities hostile blacks have to show hostility toward whites (contact).
5. The extent to which those opportunities are used to express hostility (transmission).
6. The extent to which the expression of black hostility toward a white person produces a feeling of hostility in the white person (acceptance).
Solutions: Thus, if we create public policies that reduce the value of a1 and/or a2 we can reduce the rate of increase in interracial hostility (we will set aside for the moment the need to de-hostilize individuals that have already become hostile). In other words, we need to change at least one of these six factors. What sorts of public policies might do this?
Some factors to consider:
¨ is reducing interracial contact possible? desirable?
¨ will punishment-based or incentive-based policies be more successful?
¨ can public policy alter individuals’ reactions to expressions of interracial hostility? Will non-policy based approaches be more successful at this?
¨ can one of the racial groups unilaterally stop the spread of interracial hostility?
¨ how have the various strategies of civil rights legislation, social movements, etc., affected the values of these variables?
¨ are there solutions to this problem that are technically efficient but socially unacceptable?
¨ at t=1, is it more effective to reduce a1 or a2? what about at t=10? how does this affect the desirability of public policy alternatives?
¨ what would happen if we introduced more racial groups into the model?
¨ what if we were to add variables to the model to account for racial friendliness? In addition to making the model more complex, how would this affect outcomes?
Conclusions: So, this has given us a lot to think about. Formal models can’t tell us how to run the world, or even what’s going on in the world. Additionally, they are only valid if the assumptions they make about the world are also valid. But they can help us isolate and identify relationships between various stimuli and responses. Their elegance also allows us to see cause and effect by mere manipulation of the value of variables, as opposed to trial and error in the real world. Models cannot replace empirical investigation, but at certain stages in the development of our thoughts about some aspect of political science, they can be an invaluable tool.