The Dosadi Experiment (1977) is a science fiction novel written by Frank Herbert. It is the second full-length novel set in the ConSentiency universe established by Herbert in his novelette The Tactful Saboteur and continued in Whipping Star.
Jorj X. McKie is a Saboteur Extraordinary, one of the principals of the Bureau of Sabotage, and the only human admitted to practice law before the Gowachin bar as a legum (lawyer). While meditating in a park in BuSab headquarters McKie is mentally contacted by the Caleban Fannie Mae, a female member of a species of unparalleled power from another dimension whose visible manifestation in this universe is the star Thyone in the Pleiades cluster
Generations ago, a secret, unauthorized experiment by the Gowachins was carried out with the help of a contract with the Calebans. They isolated the planet Dosadi behind an impenetrable barrier called "The God Wall". On the planet were placed humans and Gowachin with an unstable form of government, the Demo-Pol. The planet itself is massively poisonous except for a narrow valley, into which nearly 350 million humans and Gowachin are crowded under terrible conditions. Senior Liator Keila Jedrik starts a war that will change Dosadi forever.
In the story Jorj travels to Dosadi and escapes with Keila after engaging in ego sharing. This gives them the ability to swap bodies and thus by using a hole in the contract sealing Dosadi they can escape via jump gate. Once free, by legal manoeuvring the Dosadi population is unleashed upon the ConSentiency for good or ill.
A theme in Dune is the realization that controlled breeding or developmental manipulation can backfire and create unintended effects. In Dune, the Bene Gesserit attempt to breed a superbeing called the Kwisatz Haderach who is nevertheless under their control, but exposure to the environment and culture of Dune causes Paul Atreides to escape their grasp. In The Dosadi Experiment, McKie is bred to become a human legum of the Gowachin Bar, but exposure to Dosadi and its culture causes him to become 'more Dosadi than Dosadi' and turn the tables on his own handlers.
Likewise, the creation of a hyper-stressful environment as an incubator for the invention of a technological breakthrough occurs in Herbert's book Destination: Void, in which a crew of clones is placed on a spaceship designed to fail, necessitating the invention of an artificial consciousness to continue the mission, with destruction as their only alternative. In that case, the monster they create is Ship Who Is God. In Dune again, the Fremen are a religious sect in retreat that colonizes the desert planet Arrakis, a horrible environment in which the harshest conditions breed the most brutal survival behaviours, creating a population dangerous to the universe at large should they escape with conquest in mind (as they do in the sequels).
There are also parallels between the society on Dosadi and that described by anthropologist Colin Turnbull in his book The Mountain People (written in 1972, 5 years before The Dosadi Experiment). That book describes a Ugandan tribe, the Ik, whose conditions are so desperate and impoverished that they also have learned to survive at whatever cost, up to and including the lives of their own families.
The terrifying but vague "sleeping monster" that McKie and Jedrik encounter when they undergo their male/female ego-sharing may be the same phenomenon in Dune that frightened Bene Gesserit Reverend Mothers away from exploring their male racial memories.
Another theme is substance addiction. Many inhabitants of the Dune universe use the spice/drug melange to achieve heightened awareness and to increase longevity. However, through excessive consumption, some users (particularly the Bene Gesserit) become addicted to the point at which prolonged withdrawal results in death. In the universe of the ConSentiency, myriad drugs are used by the denizens of Dosadi. Addiction and the power play which it supports are touched upon, as they are in Dune, but the drugs of Dosadi do not produce any desirable effects upon their users.
On the other hand, this also may be a point of difference between the two universes, as, in Dune, it is observed that "The sleeper must awake," whereas in The Dosadi Experiment, "The sleeper must sleep." Another difference is that in Dune, gaining power seems to be associated with concentration falling from conscious asceticism, whereas the same is not true in The Dosadi Experiment. The Bene Gesserit consider the comfort of chairdogs to be distracting and even distasteful, whereas McKie sees no disadvantage in wishing to live with such comforts, and the comforts do not prevent him from becoming "more Dosadi than Dosadi."
A clear difference between the universes is that of the presence of intelligent aliens. Dune is inherently a tale about the evolution of humanity; only at the barest edges do we see anything that is certain to be alien (e.g. - futars), whereas essentially all characters are human in form, Leto II, part sandworm, being the sole exception. Plenty of questions are raised as to whether people "remain human," but that is a psychological question, not a question of the form of their body. In contrast, the ConSentiency has many alien races interacting together.
Finally, the use of some form of ego transfer to grant immortality is revealed as a practice of the Bene Tleilaxu in Heretics of Dune. In the Dune universe, ego transfer occurs as a result of actual cloning, where the clones recover the memories of their ancestors by undergoing a carefully staged moment of great stress.