So we know that our beliefs and expectations can be manipulated, which is why we do trials where we control against a placebo, where one half of the people get the real treatment, and the other half get placebo.
Sabemos que as nosas  crenzas e expectativas poden ser manipuladas, por iso facemos ensaios onde comparamos un control  cun un placebo: a metade da xente recibe o  tratamento real e a outra metade, o placebo.