Animals in Translation (18 page)

A lot of interesting research has been done on the
opioid theory
of love and friendship using the drug
naltrexone,
an
opioid antagonist
that blocks opiates in the brain. Jaak Panskepp is best known for this research, and I've also done an experiment with Nicholas Dodman, who is a professor in the Tufts University School of Veterinary Medicine and also the author of
The Dog Who Loved Too Much.
Doctors use naltrexone to treat heroin and alcohol addictions, but it also
blocks endorphins, so researchers can use naltrexone experimentally to see what happens to social attachment and distress calls when an animal's opioid system isn't working.

What researchers have found is that animals get much more social when they take naltrexone, which is exactly what they hoped they'd find.

Here's how it works. Naltrexone blocks the effects of opioids in the brain, which feels bad. Functionally speaking, having your opioids blocked is the same as having low opioids. Social contact raises opioids in the brain, which feels good. In theory, animals who've taken naltrexone ought to get more and more social, because they are trying to raise their endorphin levels back up to where they were before the naltrexone blocked them. An animal whose endorphins are low should try to raise his endorphins by getting more social contact the same way a heroin addict whose heroin levels have gotten low will want to use more heroin.

That's what happened in the experiments. Dogs on naltrexone wagged their tails more and monkeys groomed each other more. Animals taking naltrexone become more sociable.

I haven't heard of any experiments on naltrexone in typical humans, but Dr. Panksepp has done a lot of work using naltrexone in autism, because he thinks some autistic people may have
too many
natural opioids in their brains.
High
levels of opioids lower social desire, which is why heroin and morphine addicts withdraw from social contact. They stop feeling the need for other people. Dr. Panksepp thinks some autistic children may be like heroin addicts. They don't feel the need to interact with other people because their opioids are too high.

He based this theory on the fact that some autistic children have abnormally low pain sensitivity, which might come from too-high opioid levels, and also on the fact that some autistic children do not cry real tears. When you give opiates to animals they don't cry at all, so it's possible an autistic child who cries without tears might have a problem in his opioid system.
²⁴
(Animal researchers use the same word to describe crying in animals as in people.) Dr. Panksepp also thinks autistic children who like very spicy, salty, or hot foods might have naturally high opioid levels, so they might get more social tak
ing naltrexone. So far he's found that about half of the autistic children he's treated have gotten more social when they take low doses of naltrexone.
²⁵

F
EELINGS FROM
M
Y
S
QUEEZE
M
ACHINE

When I saw the cattle in their squeeze chute and got inspired to build a squeeze machine for myself, at first I was thinking only about the calming effects of deep pressure. So I built it with just two hard plywood boards, without any padding or cushions. All autistic children and adults like deep pressure. Some of them will put on really tight belts and hats to feel the pressure, and lots of autistic children like to lie underneath sofa cushions and even have a person sit on top of the cushions. I used to like to go under the sofa cushions when I was little. The pressure relaxed me.

Then gradually I started to improve my squeeze machine by adding soft padding to the boards, and I got a second feeling that was different from just feeling relaxed and calm. The pads gave me feelings of kindness and gentleness toward other people—social feelings. It also made my dreams nicer. I would have dreams about petting puppies, or being out in the green pasture at my aunt's ranch with the blue skies overhead. Things like that. The hard boards made me feel physically calm, but the soft padding made me feel
social.
I had to have the nice feeling of being held to have nice thoughts about people.

My experience reminds me of the famous experiments back in the 1960s by Harry Harlow at the University of Wisconsin. He tested baby monkeys to see whether they would prefer fake mothers made of wire or of soft cloth. All the babies preferred the soft cloth mother, even when all the milk came from the wire mother. The contact comfort was more important to them than the food.

I noticed something else with my padded squeeze machine, too. After I started using it, I would sometimes feel worse the next day, more anxious. That didn't happen with the hard plywood. Today I think I probably felt more anxious because the soft squeeze machine was activating my opioid system. It was making me have nice social feelings, and it was also making me physiologically dependent on my
machine the same way people are dependent on social contact to keep their endorphin levels up. When I used the squeeze machine and raised my opioids, then didn't use it again for a few days, I was having a withdrawal. I was developing a social dependence on my squeeze machine.

I think the squeeze machine probably also helped me have more empathy, or at least more empathy for animals. When I first started using the soft version of the machine, in my late teens, I didn't know how to pet our cats so they really liked it. I always wanted to squeeze them too tight. Then after I used the soft machine I thought, “I have to make the same feeling I have go to the cat.” I walked out of the room and the cat was in the hall, and I started stroking him, trying to transfer the feeling I had in the machine. Before I used the soft squeeze machine BeeLee used to run away because I always squashed him. But that day he started purring and rubbing up against me. I realized, “I know how to pet kitties so they like me.” This happened immediately after I used the soft machine for the first time. I remember the exact moment I did it.

Autistic children never know how to pet animals the right way, so you have to teach them. Usually they want to squeeze the animal way too tight. I talked to one young woman with Asperger's syndrome about her pet cat. Asperger's syndrome is a form of autism where the person's IQ is normal and language comes in on time. (A person with autism can also have a normal or a high IQ, but to have the diagnosis of autism you have to have had a language delay.) She told me her cat didn't like to be squeezed, but since she liked to squeeze the cat she kept on doing it. I told her, “You must not squeeze the cat,” and I stroked her arm to show her how she had to touch her cat.

Even a lot of normal people don't realize that you have to
stroke
animals, not pet them. They don't like to be petted. You have to stroke them the way the mother's tongue licks them.

So far no one has studied empathy and the opioid system. Researchers have just measured things like distress calls. But my experience with the cat might mean that
social intelligence
may be partly based on the opioid system, too, not just social attachment and dependence.

S
QUEEZE
M
ACHINES FOR
P
IGLETS AND
B
ABY
C
HICKS

There have been two experiments on squeeze machines for animals, one by Dr. Panksepp and one that I did with Nick Dodman. In Jaak's experiment, he hollowed out a little foam square to make a squeeze machine for a one-day-old baby chick. He put a little fluffy chick inside the foam square with its head sticking out, and then counted how many distress calls the chick made when it was separated from its mother. Inside its foam square the chick cried a lot less, which is what Jaak predicted would happen.
²⁶
That's evidence that the soft squeezing raised the chick's brain opioids, since animals stop crying when they are given opiates. It's not just social contact that raises endorphins in the brain.
Social touching also raises endorphins.

The study I did with Nick didn't turn out as neatly. We built a squeeze machine for a piglet out of two boards wrapped in foam rubber and covered by gray plastic upholstery material. The two boards were inside a little pen with a gate at the front, and on the other side we had another piglet standing there facing the piglet inside the squeeze machine so they could touch noses through the gate. We had to have the other piglet because if we didn't the lone piglet would just go crazy with anxiety.

We didn't actually squeeze the piglet in the squeeze machine, because we wanted to see whether he would
squeeze himself
against the foam boards after we'd given him naltrexone to block his opioid system. We were predicting that he wouldn't squeeze himself against the foam, because he wouldn't be able to feel any of the good endorphins that come from physical contact. Squeezing himself wouldn't feel any better than not squeezing himself.

Normal baby pigs love to snuggle into each other. If they get anxious or excited during handling they stick together so tightly you can't get them apart. Hog farmers call it “squealing super-glue.” So if you put a normal piglet inside a piglet squeeze machine he'll snuggle down against the foam and go to sleep, probably because his endorphins help put him to sleep. It's a little like a heroin addict “nodding out,” only it's natural and healthy. (Dr. Panksepp has
done an experiment with baby chicks showing what happens if you raise their opioids by giving them a low dose of an opiate drug and then hold them in your hand. The baby chick will stop cheeping, snuggle right down, and close its eyes. Raised endorphins probably have exactly the same effect.)

So we predicted that naltrexone would prevent the piglet from snuggling into the foam and going to sleep, because he wouldn't be able to feel the effects of higher endorphins in his brain, and he wouldn't get sleepy. He would stay awake and stay standing up.

That wasn't exactly what happened, though. At first the piglet couldn't settle down at all, so we were right about that. But after a while he managed to do it. All the naltrexone seemed to do was delay the contact comfort response. Jaak Panksepp found the same thing with his baby chicks. Even when he completely blocked their opioid systems, they still settled down eventually.

I think the explanation may have to do with oxytocin. Oxytocin also goes up with physical contact, and I think what might have happened is that every time the pig briefly squeezed himself against the soft foam he probably raised his oxytocin a little more until finally his oxytocin levels were high enough to compensate for the missing opioids and he settled down.

This research is important for people with autism. A lot of autistic children can't stand to be touched. I was like that when I was a little kid. I wanted to feel the nice social feeling of being held, but it was just too overwhelming. It was like a tidal wave of sensation drowning me. I know that doesn't make sense to people who aren't autistic, and the only other way I can think of to describe it is being in the ocean with waves washing over you that keep getting bigger and bigger. At first the waves feel good, and the sensation is soothing and relaxing. But as the waves get stronger and more powerful you feel like you're starting to drown and you panic.

Being touched by another person was so intense it was intolerable. I would start to panic and I had to pull away.

That's why I would get under the sofa cushions, because I could control those. I could let that good feeling wash over me, and if it got too intense I could stop. But when people hugged me they wouldn't stop. I had this one very affectionate big, fat aunt and
when she hugged me she had this horrible perfume so there was that smell overwhelming me along with the touch. I had to get away.

When I first used my squeeze machine it was overwhelming, too. I had to force myself to relax into it and let the good feeling wash over me. Today I think it's very important to desensitize autistic children to touch, because all children need to be touched. It's not that autistic children don't want to be touched; it's that their nervous systems can't handle it. A lot of occupational therapists have ways to work with an autistic child so that touch starts to feel much less intense and more normal. That's important.

Nonautistic people can have problems with touch, too, of course. Over the years, what's interesting is that I've found that some guys hate the idea of the squeeze machine because they don't want to give in to it. Girls always like it better than the guys. Big macho guys especially don't like it, and anyone who's claustrophobic hates it. With men, I've found that a lot of guys also don't know how to pet animals right. They'll pet them too roughly, and the animals don't like it. A lot of times men play too roughly with dogs, too, at least in my experience. I don't know whether petting is related to opioids or oxytocin or maybe to both, but men have lower levels of oxytocin than women, so maybe when a man has a rougher way of touching animals than most women, it's related to oxytocin. I don't think it's clear whether men have overall lower levels of oxytocin, but their testosterone may make them less responsive to the oxytocin they do have.

A
NIMALS
L
OVE TO
P
LAY

Nobody knows why animals love to play so much, but they all do. That's where the emotion of joy comes from, the play circuits in the brain. When big old huge dairy cows are let out in the spring, after spending the whole winter cooped up in the barn, man, they just jump around all over the fields like little calves. It's the same feeling young animals have when they play.

We don't know as much about the brain basis of play as we do for curiosity, love, and sex. One thing we do know is that you don't need any neocortex at all to play. That's not to say the neocortex never lights up during play; it probably does. But if you remove the
neocortex, an animal will still play. And if you damage the frontal lobes, which are the decision-making, responsible part of the neocortex, an animal actually plays
more.