Why was Stalin so opposed to genetics?

While not an answer exactly, I would like to point out that Soviet leadership sought to apply and vindicate Communist theory in many arenas. I was told that chess as a sport was important to them because somehow it illustrated dialectical materialism. I believe also that Lysenkoism also was in some weird way proof of Marxist theory. I may have this wrong and the whole thing sounds like nonsense to me, but I have someplace heard/read this kind of thing.

Pretty sure Stalin didn't care much either way. He just favored those who said the right words and played into his (naturally, quite limited) understanding of science, biology and genetics. And many of those guys were quite happy to promote themselves at the expense of the others; and the party bosses could not see the difference - especially if the science was complicated and both sides could not show immediate results... or one of the sides fudged the results and used that to destroy the opponents. It still happens everywhere around the world - but alas in the USSR of 1930-1950s those scientists were unlucky to live in the country where the debate resolution was so commonly done via secret police, trials and prison time (or worse).

It was a requirement for science to match ideology rather than just deriving objective conclusions.

Ideologists assumed that accepting gene theory makes easier to justify large inequality between social classes and nations, something that Marxists are formally against. Or Honorary Aryan. Or act of creation as origin of life.

While existence of genes does not actually prove these three theories beyond doubt, accepting genetics is just suboptimal from the ideological point of view.

First of all, Lysenko did not oppose genetics in general, he was against so-called "formal genetics". He was the director of the Institute of Genetics of the Academy of Sciences of the USSR since 1940.

In 1939 he said in a speech:

Unfairly comrades Mendelists allege that we profess closing of Genetics (...) Genetics is necessary and we struggle for its development and flourishing

He authored a number of works on genetics, including

• "About two directions in genetics" (1939, conference theses)

• "Agrobiology. Works on questions about genetics, selection and seed breeding" (1949)

• Article "Genetics" for Encyclopedy of Agriculture and for Great Soviet Encyclopedy (1946)

• "To the question about old and new genetics" (1947)

Odessa Institute of Selection and Genetics was named after Lysenko in 1948.

As you know in 1933 the USSR experienced a heavy hunger, or at least the Soviet leadership thought it was hunger. It prompted them to search an effective method to quickly increase productivity of agriculture.

There were several reasons why it was Lysenko who enjoyed the government's support.

• Lysenko promised quick, immediate results, while traditional genetics at the time did not bring practical results at all. Lysenko pointed that even if he had not a complete theory, it was the practical results that matters. At the time among Soviet scientists there was a widespread belief that many spheres of bourgeois science are not practical, pure scholastic and drain resources. To achieve practical results Lysenko used a number of methods of various effectiveness, such as vernalization, nested planting and others. Some of his methods such as "plant chasing" proved effective and used to this day in Tajikistan and Uzbekistan.

• Lysenko developed an image of a native ethnic Russian peasant "just from a plow" who learned himself, an image closely associated with Lomonosov, while many of his opponents (including Vavilov) were ethnic Jews whom Stalin did not trust. Vavilov in addition was of bourgeois origin. Many also thought that Jews have no natural capabilities and scent in the sphere of agriculture, which ethnic Russian peasants have by nature.

• By the Lysenko's followers it was claimed that traditional genetics gives scientific support to racism, eugenics and social inequality. This was a sound argument in the face of the advancing Nazism. Some felt that even if traditional theory correct, the danger of it being applied to humans makes it worth to oppose it by any means.

The modern period was characterized by a belief that the world could be reinvented in light of the superior understanding provided by modern thinking. The communists were major proponents of this movement. The result of this ego-driven idea was that it attracted people who believed their understanding of the world was superior to a traditional view hewn from generations of experience. These self-involved types rose to power through sheer bullying and never had their ideas tested by real world situations until they came to power. The actual experience of their ascent to power taught them that truth does not rule but power does. They became confused about how the world works because their solutions worked on a short term. Killing opponents did eliminate the problem. They soon came to believe that they could define the truth through power and enforce it through oppression and propaganda.

To answer your question "why communists hated genetics" - it was because they are absolutely normal human beings. Lysenko held a bit of power and did everything in his power to maintain it, including calling out his academic competitors as lacking faith in the one true cause. Since the leadership was cut from the same cloth, they went along with it, believing that they could decide what was true anyway.