DAVID GREENE, HOST:
Now, this investigation and manhunt that Dina and Steve just spoke about, they come in the wake of that marathon bombing in Boston Monday. In Texas, we had this deadly explosion at a fertilizer plant. That is a lot of tragic news to digest in a week. And there is a human tendency to think that these events are somehow connected, even when they're not.
Before last night's events, we called in Shankar Vedantam, who regularly joins us to talk about social science research. We asked him to talk about the psychology of a crazy week like this.
Shankar, thanks for coming in.
SHANKAR VEDANTAM, BYLINE: Happy to be here, David.
GREENE: So what do you make of the fact that we've had really just a crazy week with a lot of sad events to digest?
VEDANTAM: You know, I think the thing, David, that strikes me is how we tend to connect these events in our heads. So you know when I heard about the Texas explosion, the very first thought that went through my head is, is there a connection here with what happened in Boston?
GREENE: Yeah. The same thing here.
VEDANTAM: And you know, human beings do this all the time. When a series of things happen - especially when they're bad things - we look for connections between them. And social scientists have talked about this for more than a generation now, this phenomenon called illusory correlations, where we connect things that are actually unconnected just because they happen together at the same time.
GREENE: We should say there is no connection that we know about between what happened in Boston and in Texas. But you really are making a different point here. Why do we have that reaction? Why do we want things to be connected?
VEDANTAM: Well, I'll give you the pop-culture analysis and I'll give you the science analysis.
VEDANTAM: I think from a pop-culture point of view, you know, people are watching all these crime shows on television. You know, you have "CSI." And in these shows, completely weird and unrelated things happen that at the end of 48 minutes are all pulled together very neatly in the script.
GREENE: By the scriptwriters. Yeah.
VEDANTAM: By the scriptwriters. And they all do come together. And I think in many ways we're applying the same kind of model when we think about actual news events.
GREENE: We believe we're living in an episode of "CSI" in a way.
VEDANTAM: You know, in a way. But there's also, I think, a scientific reason why we connect the dots. You know, in our evolutionary history, connecting the dots was the only technique we had to try and figure out why bad things happened. You know, we didn't have satellite images. We didn't have scientists with their models to tell us this is why people get sick or this is why a tsunami strikes. And so connecting the dots was the way our ancestors said let's be careful about bad things that could happen to us. Since our brains are sculpted by evolution, when I'm biking to work today in Washington, D.C., and a car swerves very close to me, the next day when I'm biking on the road, I remember that spot on the road where it happened because we are actually connecting those events. We're saying that stretch of road is connected with this bad thing that happened to me. I'm going to avoid that stretch of road tomorrow. And at a scientific level it makes no sense because the same car isn't there anymore...
VEDANTAM: ...but at the sense of survival it's actually very practical.
GREENE: You know, one thing that strikes me, this week's events, we don't know why a fertilizer plant blew up and it leaves a lot of uncertainty that feels uncomfortable in a way.
VEDANTAM: Yeah. And I think it's the uncertainty that actually helps prompt this desire to connect the dots. And I think we've seen this time and time again, when you don't know, our mind goes searching for those explanations, and I think that's utterly human. The problem is if policymakers start making the same connections without evidence, because when they start doing that, you know, that's when you'll get racial profiling and that's when you get internment camps.
GREENE: One of the other differences in today's society compared to decades ago, we see all of these images on cable news, we have social media. I mean we have video of the fertilizer plant blowing up. How does that affect, you know, how we consider these things?
VEDANTAM: You know, one thing to think about, David, is that in our evolutionary past when, you know, these negative things happened to us, they were invariably things that happened in our local environment, because all the events that we knew about probably took place within a five-mile radius from us.
GREENE: Were right nearby, yeah.
VEDANTAM: Today that's just not the case. But television brings those images together and in our minds can make them feel almost like they're local events. So that the Boston incident and the Texas incident, we're watching it on the same screen in consecutive news stories and they can feel connected in a way that are not really connected. And I think this actually points to something that public health officials always advise when you have these disasters, which is to limit the amount of time you spend watching very graphic and violent images on television because they can create false impressions in your head and potentially affect your psyche.
GREENE: We've been talking to NPR's Shankar Vedantam. And Shankar, we'll hope for a week of better news next week. Thanks for coming in.
VEDANTAM: Thanks, David.