The measurement problem, plainly
Quantum theory has two rules that sit awkwardly together. Left alone, a system evolves smoothly and predictably by the Schrodinger equation, spreading into a 'superposition' of possibilities: an electron can be in several places at once. Yet whenever we measure it, we find one definite outcome. The measurement problem is the puzzle of how, and why, the many smooth possibilities become one sharp result.
For decades this was framed loosely as 'observation' making the difference, and that single word has caused endless confusion. In ordinary speech an observer is a person watching. In physics it means something far more modest: any interaction with a large system, a detector, a photographic plate, a stream of stray air molecules, that records the result. No awareness is required.
Where 'consciousness causes collapse' came from, and why it faded
In his 1932 Mathematical Foundations of Quantum Mechanics, John von Neumann showed that the theory lets you place the dividing line between the quantum system and the classical measuring chain almost anywhere. Eugene Wigner, in the 1960s, took the boldest option: perhaps the chain ends only when a conscious mind becomes aware of the result, so consciousness itself causes collapse. This became known as the von Neumann-Wigner interpretation.
It was always a minority view, and it faded. Wigner himself abandoned it, partly because it courts solipsism: if only minds collapse wave functions, what happened during the billions of years before any mind existed? A 2011 survey of quantum-foundations researchers found only a couple of respondents willing to grant consciousness a special physical role. Crucially, no experiment has ever detected a mind influencing a quantum outcome. Fringe claims that meditators can bend interference patterns have not survived scrutiny; physicists point out that the predicted loss of interference follows from ordinary measurement, with or without an aware observer.
What actually explains the click: decoherence and the interpretations
The modern workhorse is decoherence. When a quantum system touches its environment, it becomes entangled with countless particles, and the delicate interference between its options is scattered into the surroundings almost instantly; a floating dust grain loses its 'quantumness' in a tiny fraction of a second. Decoherence explains beautifully why we never see macroscopic superpositions and why detectors behave classically, though by itself it does not say why one particular outcome ends up being the one we experience.
That final step is where interpretations differ, and none of them needs consciousness. The Copenhagen view treats the quantum state as a tool for predicting measurement results. The many-worlds interpretation says every outcome happens, each in its own branch, so nothing truly collapses. Relational and QBist views hold that outcomes are real relative to a physical system or to an agent's information, again without minds working magic on matter. Wojciech Zurek's 'quantum Darwinism' adds an account of why we all agree on the same classical reality: robust states get copied many times over into the environment.
The bottom line
So the honest answer is no: consciousness does not collapse the wave function, and there is no evidence it could. The genuine mystery, why nature offers possibilities yet yields single facts, is real, and thoughtful physicists still argue about which interpretation best resolves it. But that debate is about physics and measurement, not about the power of the human mind to reach out and change an atom.