Can We Trust Our Five Senses?

Earlier today one of my students asked what I thought was a fairly odd question. She asked me, “How do we know we can trust our senses?”

At first I thought she was asking about senses in the terms of instinct because I have some very strong views on trusting our instincts, but she clarified that she was talking about our five senses which threw me off, but gave me something to think about.

Most of us have the five traditional senses of touch, hearing, smell, sound and taste.

There are also other senses that include sensing pain, temperature, movement, and balance. We are born with these senses. They are natures ways of helping us navigate through our world while both experiencing pleasure and avoiding pain. They help us throughout the day in small ways as well as major ones such as keeping us safe from danger.

Many times we don’t even realize how much we depend on our senses and take them for granted. Since they have been with us from birth, we tend to trust them even when they occasionally deceive us. In fact, our senses are so rarely wrong, that the times they are wrong are usually quickly forgotten and not seen as proof that our senses have failed us.

Our senses normally always do their jobs. They sense something and relay it to us, and then it’s up to our brains to make since of what our senses are telling us. Our senses are so powerful and important that they are often locked into our minds and paired with some type of memory or emotion. Some of it is in our recent memory and some of it is in our collective unconsciousness.

For instance, almost universally people around the world naturally panic or get startled at the sight of a snake. This is not a learned behavior, but seems to be passed down through our collective unconsciousness where our ancestors had to learn to avoid certain snakes if they wanted to survive. Even young primates in lab studies who have never been around other older primates or snakes before, demonstrate this natural fear of snakes. This survival instinct is imprinted in our DNA and is translated through our sense of sight.

The same goes with hearing a loud explosion. Our sense of hearing immediately make us become hyperaware and attentive. Our arousal system revs up to prepare us to either run from the noise or get ready to fight for our lives. During this and other times where we may be in danger, all of our senses come together to try to help us make sense of what is going on and what we need to do.

For instance, in the case of an explosion, not only will our hearing help direct us in the direction of the noise, but our eyes will become more keen and focused so we can try to get a better view of what is going on. Our sense of smell may be trying to figure out what odors are in the air, if they are dangerous and if they are getting stronger. Our skin will be aware of changes in temperature, such as heat to let us know if we are at a safe enough distance from the explosion or if we need to move further away. All in all, our senses exist to protect us and keep us safe.

Another example is one time I ate some bad fish that gave me severe food poisoning. It was a miserable experience that felt like it last several days. Once I got better, whenever I saw or smelled fish I automatically felt sick. My body, my senses, were reminding me that the last time I ate fish I got really sick and so they were helping me avoid getting sick again by giving me a safe reminder.

This is called a food aversion and is a way the brain uses the senses to protect us from getting sick or possibly dying. The same thing can happen when you taste something that may not be safe to eat or drink, which is why when testing to see if a gallon of milk is still okay, one of the first things most people do is smell it, they may then look at it for evidence that it’s not good and if all else fails, they will taste it.

Even with all of that, there is a chance that our senses will fail us and we drink the milk because it “checked out” and we still end up sick. That doesn’t mean that we won’t trust our senses again in the future, it just means that we may be a little wearier in trusting them when it comes to spoiled milk. However, because they are usually so consistently reliable, we are not likely to consciously second guess them the next time we smell smoke, feel a rain drop on our skin or touch something that feels too cold or hot to handle without intense pain.

Like I stated earlier, our senses are such an integral part of us that much of them are stored into and attached to our memories, which explains why someone suffering from post traumatic stress disorder may have a flashback or experience anxiety whenever they taste, touch, smell, hear or see something that reminds them of a tragic incident.

For example, a woman who was eating sausages the moment she saw her husband have a heart attack and die right in front of her, may feel sick, scared, anxious or sad anytime she sees, smells or taste sausages in the future. This is one of the times when our senses may fail us because in this example, her senses will be reminding her of the tragedy and setting off an alarm of an impending tragedy that is unnecessary.

As a matter of fact, in many instances of post traumatic stress disorder, it is our senses “failing” us in a sense. In actuality they are doing their jobs, trying to protect us and giving us warnings that make us hyper-vigilant, anxious, irritable or causes flashbacks, but they are wrong because we are not in that situation any more where we need to be ready to fight or flight. In this case, our senses are giving us false alarms.

Another time when our senses may fail us is when we smell something that reminds us of something else. Like once I was in class and there was an air freshener in the class that immediately reminded me of my dentist’s office. And there are those strange times when I think I am about to drink a Coke in a glass, but it’s really Pepsi, but my sense of taste is prepared for Coke, so when I take a sip it automatically tastes disgusting. Although I like Pepsi, my sense of taste was expecting Coke and registering the taste back to my brain as “disgusting”. It’s my brain’s way of letting me know that I am not drinking what I thought I was by using my sense of taste. As soon as I realize it is Pepsi and not Coke, the taste of “disgust” automatically goes away.

Without even one of our five senses it’s difficult for us to navigate our world safely. In a study done at the University of Gothenburg in Sweden, they found that men born without the sense of smell, a conditioned called anosmia, found fewer sexual partners than other men and women with anosmia felt more insecure in their relationships than women without the disorder.

For the most part, our senses are completely reliable. They are our natural weapons against an ever changing and perilous environment. They served our ancestors for centuries, which is why we have survived. Those who didn’t trust their senses likely died from poisonous snake or spider bites, extreme hot or cold temperatures, poisoning, fire, etc. Our ancestors learned to trust their senses, which is why we are here.