My oldest son got the book Dragons Love Tacos for Christmas this year.
In that book there's a line that reads "Hey Dragons! Listen to me! Do not eat those tacos! They are too spicy!"
I have this line memorized now because for the last six weeks when my son is eating something he asks us to "do the dragon." In other words, he wants us to tell him "Hey! Listen to me! Do not eat that (insert food)! It's too spicy!"
At first my husband I thought it was super cute. That is until our son started to think that his food was actually spicy and refused to eat anymore of it.
It didn't matter if it was his favorite dish or a sugary treat, as soon as we "did the dragon" he wouldn't touch it claiming it was "too spicy!"
It's funny how kids' brains work this way, but it's not just kids, it's adults too. Tell someone they are hurt, and they will (usually) start to feel worse. Tell someone they are fine and they will start to (usually) feel better. This is why placebos work. The placebo didn't actually work. The person's belief that the placebo worked worked. The food wasn't actually spicy, it was my son's belief that the food was spicy that makes it spicy.
This concept extends far beyond the medical world and the world of children. It also works in workplace learning.
Here's a scenario most of the learning professionals have faced. A stakeholder comes to you and says: "I need training!" We start to look into the problem and discover that training isn't going to solve the issue. Maybe the system is broken and we suggest that we fix the system. The stakeholder agrees and the problem is fixed and people start performing better. But, would they perform even better if we also delivered "training" as the stakeholder requested? (Note: I am not talking about an actual learning experience. What I am talking about here is a quick micro-learning, a just in time eLearning that sums up - or in other words - communicates what the stakeholder wants people to know.)
From my experience, I have seen the most successful learning experiences being the ones where we identify the root cause of the problem and fix it, but also deliver a traditional "training" (usually a quick eLearning that communicates something but offers limited to no practice). This is because of the placebo effect. It's not the actual "training" that worked to solve the problem. It's the belief that training will solve the problem makes it so the stakeholder sees less of the problem.
With that, I have one piece of advice to offer: "Instructional Designers, Listen to me! Use that placebo effect."