Ok, this may sound like a silly job interview question and something more in line with common job interview etiquette than the substance of the interview itself, but experts say that when someone does something for you, they are actually slightly more positively inclined towards you. It’s called the Ben Franklin effect: a person who has performed a favor for someone is more likely to do another favor for that person. So even if you’re not a thirsty job candidate that day, just take the water, for goodness sake!