Measuring aggression in the lab is hard

Psychologists often study aggression in lab-based settings.  However, some people are unconvinced that commonly-used lab-based aggression paradigms actually demonstrate aggression, which, they claim, limits the evidentiary value of results from studies that use those paradigms.  Rather than dig in heels, I have tried to think of ways that researchers can frame their criticisms to make these discussions more productive.

I believe that most criticisms of lab-based aggression paradigms take on one of two flavors: The behavior was not believed to have been harmful or the behavior was not believed to have been caused by a cognitive process involving aggressive cognitions. 

The definition of aggression identifies the sources of criticisms

Aggression is a behavior that is done with the intent to harm another individual who is believed to want to avoid receiving the behavior.  Thus, to demonstrate aggression in the lab requires two factors: (a) a harmful behavior and (b) that behavior must be believed to have been caused by a cognitive process that involved an intent to harm and a belief the recipient wanted to avoid experiencing the behavior (i.e., collectively referred to as “aggressive cognitions” herein).  If both factors are present, aggression has occurred; if both factors are not present, aggression has not occurred.  Conceptually simple, yet hard to execute.

Demonstrating harmful behaviors in the lab

Neither the IRB nor most researchers will allow participants to actually harm another person just for the sake of testing a hypothesis.  So, you cannot even demonstrate an unambiguously “harmful” behavior in the lab.  This is a big deal.  It is like researchers who are interested in the phenomenon of “eating ice cream” and the IRB won’t allow participants in your lab to actually eat ice cream.  For this reason, aggression researchers must use “ethically palatable” behaviors that minimally meet the criterion of being harmful, but really don’t involve people harming one another. 

Some examples of previously-used lab-based behaviors include sending irritating sound blasts to another person (who typically do not exist), selecting how much hot sauce will ostensibly be served to a person who dislikes spicy foods, sticking pins into a Voodoo Doll of another person to “inflict harm,” choosing how long another person will hold an uncomfortable Yoga pose, etc.  It is not that aggression researchers think these are super harmful behaviors; but these are reasonable tasks that can be considered a little harmful, are quantifiable, can be done in a lab environment, don’t put anybody in harm’s way, etc.  In other words, these tasks are pragmatic, not ideal. 

Some people legitimately doubt whether these behaviors meet the “harmfulness” criterion (e.g., is a sound blast really “harmful”?).  And, I would suspect that most aggression researchers would readily concede that these behaviors are artificial, contrived, and open to debate on whether they are “harmful”.  If the opinion is that these behaviors are not “harmful,” then, by definition, these behaviors cannot be considered aggressive.  I sincerely hear and understand these criticisms.  Nevertheless, researchers obviously cannot allow participants to actually harm another person within a lab environment.  

Inferring the presence of aggressive cognitions in the lab

It is insufficient merely to demonstrate that a harmful behavior has occurred; the cognitive process that causes those behaviors must involve, in some (usually undefined) capacity, aggressive cognitions.  If aggressive cognitions were not involved, then the resulting behavior is not aggression, regardless of how harmful the behavior was.

Aggression researchers attempt to create a context from which aggressive cognitions can be inferred.  For example, researchers may tell participants that a specific behavior (e.g., pressing a button) will cause a specific event (e.g., send an unpleasant noise) that has a specific effect (e.g., another person will experience the unpleasant noise).  Thus, observing the behavior allows the researcher to infer the behavior was done with a known intent and with a known consequence.  If the behavior was harmful and aggressive cognitions were assumed to be involved in the cognitive process that caused those behaviors, then the resulting behavior can be assumed to be aggressive.

Some critics point out that several cognitive processes also can produce the same behavior; thus, there is no reason to favor a cognitive process involving aggressive cognitions over these other cognitive processes. For example, participants may perceive a particular task as competitive (rather than as an opportunity to aggress), participants may engage in “mischievous responding,” or participants may intuit the study’s hypotheses and behave according to what they believe the hypotheses are. 

The argument goes like this.  A cognitive process with “aggressive cognitions” may cause a harmful behavior (if a, then b), but observing a harmful behavior does not necessarily imply the behavior was caused by a cognitive process involving “aggressive cognitions” (b, therefore a) because there are several cognitive processes (e.g., competition, mischievous responding, socially-desirable responding, etc.) that also can cause the same harmful behaviors (if x, then b or if y, then b).  Believing that the presence of a harmful behavior necessarily implies the presence of a cognitive process involving aggressive cognitions is a logical error known as affirming the consequent. 

Perhaps an unappreciated idea is that these criticisms cut both ways.  Just because it is possible that a “non-aggressive” cognitive process can cause a harmful behavior does not mean that it did.  For example, just because it is possible that some participants in some instances may think sending sound blasts to another person is competitive (and not aggressive) does not mean that any specific instance of this behavior does not meet the criteria for aggression.  It is possible those sound blasts in this instance were being sent with the intent to aggress against the recipient and, thus, the behavior would meet the criteria for aggression.  Further, if the same context (e.g., experiencing an insult) both causes a harmful behavior in the lab (e.g., sound blasts) and harmful behavior out of the lab (e.g., punching another person), this may cause one to slightly favor the cognitive process involving aggressive cognitions when observing the behavior in the lab.  Ultimately, researchers need to use their judgment on whether it is plausible to infer that a cognitive process involved aggressive cognitions.  And reasonable people will disagree on what is plausible.

Another common approach to inferring the presence of aggressive cognitions is to ask participants why they exhibited a behavior.  For example, you could ask participants to report whether they sent loud sound blasts to be “aggressive” or not.  If they say “yes,” then the resulting harmful behavior may be considered aggressive. 

As straightforward as this approach appears, it has its own limitations.  First, this approach assumes that participants have introspective access to their cognitive processes (which is not a requirement for the resulting behavior to be considered aggressive).  Second, the abovementioned criticisms of the processes causing harmful behaviors also apply to the processes causing participants’ self-reported motives.  For example, participants may report having done a behavior to be aggressive merely because they are being “mischievous,” or participants may intuit the study hypotheses and “play along” with what they believe the hypotheses are.   Simply put, there are many cognitive processes that can become expressed in a response of “I did that behavior to be aggressive”.

As with the criticisms of the behaviors typically observed in lab-based aggression paradigms, I sincerely hear and understand the critiques about whether aggressive cognitions are involved in the process causing those behaviors.  There is no avoiding the fact that inferring characteristics of cognitive processes is hard to do and that different researchers have different ideas of what would convince them to infer the presence of aggressive cognitions. 

Framing and addressing the critiques

It is hard to demonstrate aggression in a laboratory setting in a way that will result in wide-spread agreement.  But hard does not mean impossible.  And disagreements need not be permanent.  Here are things that I believe will facilitate discussions about the value of these paradigms. 

1.    For those offering critiques, be specific about the target of criticism.  Do you not believe the behavior was harmful?  Or do you believe there was an alternative cognitive explanation for the observed harmful behavior?  Or both?  Clarity in the critique offers clarity in the ways in which researchers can improve their methods.  Those who are unconvinced by current methods should state what methods or evidence would be convincing.  Inconvincibility is a conversation stopper.  

2.    For researchers, to demonstrate aggression you need to both (a) demonstrate a harmful behavior and (b) this behavior must be assumed to have been caused by a cognitive process with “aggressive” cognitions.  Thus, you need to both argue why you believe the observed behavior is harmful and you need to argue why you believe the cognitive process involved aggressive cognitions.  Without both of these things, you cannot claim you have measured aggression.  Keep in mind that people might will argue the behavior was not harmful, people might will argue there was an alternative cognitive process that caused the behavior, or both.  Such critiques are OK, it’s called science.  Take these criticisms seriously and use them as motivation to improve your methods.