Cognitive dissonance is everywhere. It happens to all of us and we can't really escape it. In short, it's the inner tension we feel when we hold two or more contradictory beliefs, ideas or values. We try to reduce the cognitive dissonance by, for example, ingonring the information that opposes our ideas and accepting the information that confirms them.
The Story of Trofim Lysenko
Trofim Lysenko, a Soviet biologist, claimed to have found a new way to enhance crop yields. His idea was that plants of the same species, planted closer together, would thrive better and yield more crop.
This idea was in line with the Communist ideology. Political leaders spotted him and he gradually moved up the academic ranks. Until they appointed him to the Lenin All-Union Academy of Agricultural Sciences.
Lysenko was hungry for political power. And being a faithful communist, the leaders liked his ideas. Especially the ones which supported their teachings. For example, the science of genetics, based on Gregor Mendel, was just taking-off at the time. Science widely accepts Mendelian genetics today and it states that genes encode our characteristics and we pass them from generation to generation. But despite all of the evidence that this was true, Lysenko became a harsh critic of the theory. He believed that human nature is adaptable and that we can pass down the characteristics we acquire in life to the next generations (also called Lamarckism). 
Other scientists, however, were thrilled about the new approach. And they had data to back it up. Mendel even proved it about a century before that. But instead of taking into account the evidence, Lysenko was too obsessed with the communist belief. He even went to Stalin to outlaw the Mendelian approach. Stalin agreed, Lysenko silenced his critics and guaranteed that his ideas would triumph. It decimated the Soviet science because leaders sent scientists, who didn't agree to labour camps or executed them.
Back to his original idea...it was even worse than Lamarckism. Today, we know that plants and animals compete for resources. I'm pretty sure the Soviets knew as well. But it wasn't the Soviet way. So they applied his method in the Soviet Union and Communist China.
The results were devastating. The crops were destroyed and millions died in the Soviet Union. It was even worse in China - it's considered one of the factors that contributed to the Great Chinese Famine. Druing this period, between 20 and 43 million people died of hunger.
Cognitive Dissonance In Everyday Life
I'm 100% certain every one of us experiences cognitive dissonance daily. We really can't escape it. It happens every time two opposing beliefs clash inside of us. For example, think about when you have to exercise or study. You know you have to do it, but deep down you don't want to. So you start looking for evidence to support your unwillingness to do so.
Last week, it happened to me. I had a workout plan ready, with the exclusion of Wednesday, which is reserved for basketball training. Naturally, this was my excuse for not working out. On Monday "I had no time and I will do it tomorrow." On Tuesday "I had to study this and that and I'll train basketball tomorrow, so I might as well get some more rest." On Thursday "I had to rest because of the basketball training and just can't do it." And Friday was the end of the week and I might as well not exercise if I hadn't done it all week."
This is an honest thought process - cognitive dissonance at its best. It's everywhere. We're deluding ourselves, just as Lysenko did. And we can't escape it. We can, however, acknowledge it exists and act differently at that moment. It probably all comes down to how we feel at the time, but I'm sure we can also choose how we do.
Failure And Improvement
Lysenko made his theory failure-proof by deluding himself and his leaders from the evidence available and by silencing his critics. All of this is vital for advancing in science. Many times in scientific research, it's easier to disprove a theory rather than to confirm it. When a theory and with this the researcher fails it's a sort of feedback. If the data is sufficient we can then change our theory or our approach and test it again. This process is endless and will keep happening. It's the only way science can succeed and advance.
It's also one of the ways we can improve and succeed. As I wrote about in my article about failure and improvement, failure is one of the main sources of success in aviation. Why shouldn't it also be a personal thing? But it all starts with admitting we're wrong, our theory is wrong or that we failed. And then making all the necessary changes. Lysenko failed to do all this.
Evidence, Not Ideology
When looking at Lysenko's theory, I can't help but notice his belief in the Communist ideology. Having a belief in an ideology is much different than having a belief in a valid theory. A dedicated scientist can have a belief that his theory holds and will do everything to prove it (in the boundaries of honest scientific research, of course). But having a belief into an ideology, into a theory that's based on an ideology not on the evidence, is something completely different. Firstly, it's subjective and there's no place for that in science - only for objectivity and evidence-based theories. Secondly, the problem occurred because Lysenko was part of a group. And once a group of people, who believe in the same thing forms, they not only lose the ability to be critical to one another. They also fail to accept the perspectives of people from other groups.
The evidence was there. The science and scientists were there. But Lysenko and those around him failed to learn and accept. They failed to fail. This is what ultimately contributed to millions of deaths. Such a devastating story shows us what cognitive dissonance can cause. Lysenko acted just as we could expect. He tried to lower the cognitive dissonance he felt. And the best way to do this was to accept the information that supported his ideas and simply ignore the rest. And while it's happening to us daily in the most basic things, it's fine. We try to acknowledge it and move on. Perhaps change our behaviour at that moment.
Just don't be like Lysenko.
- This is of course not entirely true. Some mutations that happen in specific cells can be passed down to the next generations. These are called "deviations from the Medelian laws", but that doesn't mean they don't hold true.