Magical thinking is the belief that a thought, an intention or a symbol can act on the physical world while bypassing ordinary causal links. Anthropologists have studied it since the 1890s, psychologists for about as long. The short cultural verdict fits into three words, "archaic", "childish", "superstitious", but the scientific picture is longer and more complicated.
I will take it in three steps.
Where magical thinking works
The placebo effect is a real physiological process. A meta-analysis by Hróbjartsson and Gøtzsche (NEJM, 2001) found it small, but that was for objective outcomes. For subjective experiences such as pain, nausea and anxiety, placebo works noticeably better. The mechanism has been traced: as early as 1978 Levine and colleagues showed that naloxone cancels placebo pain relief, and later Fabrizio Benedetti described in detail how expectation switches on specific neurotransmitter systems, including endogenous opioids and dopamine.
The upshot is simple: if you believe a remedy will help, your brain produces chemical changes that really do help. It is biochemistry triggered by a signal from above, from the higher cognitive levels. Magical thinking serves here as an interface that leads a person to a real mechanism, and the mechanism itself stays entirely material.
The same holds for prayer, meditation and ritual. Neuroimaging (Newberg and colleagues, 2001, and many studies since) shows measurable shifts in the prefrontal cortex and parietal regions during deep prayer. The neural network runs in a particular mode, and that has physiological consequences: anxiety drops, the pain threshold changes, sometimes the brain's structure changes over time. None of it requires an outside agent.
Where magical thinking misleads
Confirmation bias makes us remember the hits and forget the misses: you wished for something and it happened, so you remember; you wished and it did not, so you forget. Daniel Kahneman described this in detail (Thinking, Fast and Slow, 2011), though the effect was known long before.
The brain stitches random events into patterns and gives them meaning where there is none. That is useful in evolutionary terms (better to mistake a bush for a tiger than the other way round), but in modern surroundings it keeps producing false "synchronicities".
Magical thinking about other people is more dangerous. "I thought something bad about him and something bad happened, so it is my fault." Or: "I sent him a blessing and he recovered, so I am a miracle worker." Both are ego traps in spiritual costume. Your thoughts connect to what happens to another person only through physical channels: you called, you said something, you did something.
Where the boundary blurs
Quantum mechanics handed magical thinking an unexpected gift, the word "observer". Popularisers have been repeating the same mistake for twenty years: "if the observer affects a quantum measurement, then my consciousness creates reality".
The short physics answer is no. In quantum mechanics the "observer" is a measuring apparatus, and consciousness has nothing to do with it. Decoherence comes from the quantum system interacting with its environment; Wojciech Zurek showed this in detail in a series of papers in the 1990s and 2000s.
The longer answer is more complicated. Penrose and Hameroff argue that quantum coherence inside the brain may play a part in the moment of conscious choice. It is a hypothesis and only a hypothesis: there are fresh arguments in its favour (for example, a 2024 study in eNeuro in which a microtubule-stabilising drug delayed loss of consciousness in anaesthetised rats), it has not been accepted, and it has not been refuted. In its narrow form, "quantum processes in microtubules may be linked to consciousness", it is a testable claim. In its broad form, "consciousness creates reality", it is a slogan with no physical meaning.
What I think
Magical thinking is the forerunner of scientific thinking. It says there is a hidden link between intention and the world. Science answers that some of these links are real and run through neuroendocrine and social mechanisms, some are illusions produced by cognitive biases, and some are unknown and remain an open question.
The sensible stance is to separate: what exactly you observe, what mechanism might stand behind it, and how it could be tested. No dismissive "superstition", and no esoteric add-on about "another reality".
It is duller than "the universe is listening". It also works.