A dog is placed in a room with a globe on one side and a watering can on the other. He sees a woman entering the room from one side of the room, and handling the globe. She leaves the room, only to enter again from the same side within the next few seconds. Again, she walks to the globe and continues examining the globe.
The woman repeats this another six times, and the dog gradually stops paying attention to her: “Yeah, I get it, this woman’s really into the globe.” Following this, the dog was taken out of the room very briefly and when he was brought back — the globe had switched places with the watering can.
Now, this was an experiment run on 52 dogs, and at this point in the study, different dogs saw different things. For some, the same woman entered from the opposite side of the room and examined the globe again, and these dogs remained quite uninterested. But for others, she entered from the same side of the room as she had all along, but began to examine the watering can. These dogs suddenly perked up again, almost as if to say, “Hmm, so now she’s interested in watering cans?”
Ever looked into those big warm eyes and wondered: what’s going on in this cute creature’s head?
Whether it’s the baby or the pet poodle, the working of the mind is invisible simply because they cannot tell us what’s going on. With children and adults who can speak and answer our questions, there is some measure of insight into their thoughts and feelings! But sans speech, is there a way to get this psychological insight?
Scientists cracked this particular methodological issue with baby research decades ago, actually. Using some very clever experimental paradigms, they’ve given us amazing perspectives on how complex and sophisticated the thinking of babies really is.
Now, here’s one elegant paradigm, with some examples of how powerfully it can be used with a variety of creatures from fish to humans to dogs.
It turns out that babies, in spite of having only just arrived in our sensational world, already come wired with the ability to get rapidly bored. Yes, believe it or not, the whine “So bo-oring!” could have deep, evolutionary roots! A part of a newborn baby’s intelligence rests in its preference for novelty.
Show a baby a picture, and it’ll look at it with a great interest for a while. In a few minutes, however, it turns away, looking for something new…unless you change the picture, at which point it will switch back to looking interested. Now I must admit, I’m indulging in a little inference here. Sure, the baby looks, and looks away — but how do we really know if it’s interested or bored?
The short answer is: we don’t. All we know for sure is that it’s reacting differently. Scientists have a less evocative but more objective name for this behaviour: the habituation-dishabituation paradigm.
Why do we need experiments? Why can’t we just look at a pet we own, or a baby we know, and say “oh so this is how babies think”? After all, we’re all constantly making guesses about how the world works, supported by our own little experiences, fuelled by curiosity. Why can’t psychologists do the same?
There are a lot of factors that affect thought and action. Maybe you bought that ice cream because it’s hot outside, or because an ice cream ad from earlier was running in your head, or maybe you bought it because you saw someone across the street with one, and it looked really tempting. Chances are, you yourself won’t be able to say for sure. Because we’re constantly exposed to so many stimuli, it’s difficult to isolate one as a cause for a psychological phenomenon. One of the biggest debates in psychology, in fact, is whether certain things are influenced by our genes (or nature) or our upbringing (or nurture). But because we have the genes we have, and we can’t change who raised us, it’s difficult to say for sure.
In an experiment, a researcher has control over what stimuli you’re exposed to–at least in the short term. To go back to our ice cream example, a researcher could either increase the temperature of the room you’re in, or they could show you many ads, or show you someone else eating ice cream. Then, they can see how many people want ice cream in each condition. Instead, they could also change the flavour of ice cream so it’s not as enticing and see how many people want some then.
In other words, researchers can isolate stimuli to see what prompts behaviours, thoughts or actions from us.
From an evolutionary standpoint, it makes sense that babies would seek novelty in their perceptual environment, since it increases the scope of their learning. Once a baby has paid attention to a stimulus for some time, it’s good that it goes ‘Got it — what’s next?’
Anyway, this paradigm has now become a way to test if non-verbal creatures can tell the difference between two similar stimuli. If a baby habituates to a stimulus, and then we change it slightly, if they do not dishabituate it implies that they could not tell the difference. And of course, if they do dishabituate, we can conclude at the very least that they could tell the difference.
Using this paradigm, psychologists have discovered, for example, that infants can distinguish between colours, between faces of individuals in several species, between male and female faces, and at the ripe old age of 18 months, between objects sitting on a container and in a container. This last experiment showed babies various objects (an animal, a car, a candle, and a peg) all being placed on a container. They got thoroughly bored with that. Then they were tested with either a cap on the container, or a peg in the container. Lo and behold, the babies are dishabituated only to the peg in the container!
Take a minute to figure out what this means. The babies had abstracted the idea of ‘on’ from the several instances of seeing different objects on containers. When they saw an object ‘in’ a container, this was something new. It’s a much more sophisticated response than simply being interested in a new object!
Interesting results have been found using this paradigm with other animals too.
Zebrafish that are habituated to displays of 3 dots will dishabituate to displays of 9 dots, and vice versa. This is after controlling for the size and shape of the overall display. So the fish can count, in a way. And dogs have been a frequent object of study using the habituation/ dishabituation paradigm.
In one study, the scientists recorded the sound of different dogs barking at an intruder, and the sound of the same dogs barking when left alone and tied. They played these recordings to several other dogs (the subjects of their research), and measured heart rate as an indicator of attentiveness. When the dogs heard the intruder bark repeatedly, their heart rates went from high to low (habituation). And as soon as the new bark was played, their heart rates went up again (dishabituation).
As a clever check, they tried the same thing with two other mechanical sounds (a drill and a refrigerator) and here, the switch did not lead to dishabituation! Thus the conclusion is that dogs can tell the difference between different kinds of barks made by other dogs.
If you have a pet or a baby at hand, you could try an experiment yourself. Take any question of interest to you: for my dog, I wondered whether he responds to his name, or to the raised volume and tone of my voice when I call him.
Now, figure out a way to design the paradigm to answer your question. I decided to call out different words to him several times in the same high volume and tone, till habituation (as measured by him not turning his head toward me). Then I would call his name in the same volume and tone and look for a response!
Do try it, and you’ll realise how much thought goes into these experiments. Other variables and distractions must be controlled, or else you will never be sure of your results. Also, a one-dog case study may be pretty useless; my dog turned out to be bored from the very start and my experiment failed!
This brings me to the experiment we started with. Remember that when the woman entered from a different location but handled the same old object, the dogs didn’t dishabituate. They only perked up when she handled a different object, even though her physical movements were much the same as before.
It’s tempting to conclude that dogs are sensitive to the intentions of human beings, but to be sure, the experimenters repeated the same procedure with dogs who watched a black box substitute for the woman–the box was being invisibly manipulated to slide either toward the globe or the watering can. In this situation, dogs dishabituated to the sight of it entering from the opposite side, rather than to the sight of it stopping by a new object! Black boxes cannot have intentions, and the dogs’ behaviour showed their sensitivity to this.
Research on non-verbal creatures can reveal so much, when it is cleverly designed. Using simple methods like the one I’ve described, scientists have discovered that all kinds of animals and babies are complex cognitive creatures. It’s a humbling realisation — but an exciting one!