Tag Archives: theory and hypothesis

Darwinism: It’s Not Just a Theory

“I have a theory about really big baseball players,” The Curmudgeon has been heard to say. “When they lose it, they lose it faster than smaller players.” This “theory” is based on casual observation and not on research; it’s not like The Curmudgeon has gone into the history books, identified 50 or 100 or 500 physically large players, developed criteria for what constitutes “losing it,” and then applied those criteria to the players he selected to see if their professional decline is somehow more precipitous than their smaller colleagues.

darwinPeople have “theories” all the time: Oswald didn’t kill Kennedy, the National Basketball Association fixes the draft lottery to favor big-market teams, Obama is a Muslim, Paul McCartney died in the 1960s, things like that.

Most of these theories have one thing in common: no one has really tested them, tried to demonstrate whether or not they’re true. So in our minds, that’s just what these theories are: something that’s in someone’s mind that may or may not be true.

And that’s why people who are skeptical about evolution and the idea that man evolved from apes often say of the entire concept something like “Well, they call it Darwin’s theory, right? That’s because it’s just a theory. It hasn’t been proven.”

But it has.

The problem here is that when ordinary people and scientists use the word “theory” they’re talking about two entirely different concepts. In fact, they might as well be speaking two different languages.

An article in a 2013 edition of Scientific American explains it this way:

Part of the problem is that the word “theory” means something very different in lay language than it does in science: A scientific theory is an explanation of some aspect of the natural world that has been substantiated through repeated experiments or testing. But to the average Jane or Joe, a theory is just an idea that lives in someone’s head, rather than an explanation rooted in experiment and testing.

Course material online from the University of Oregon goes into greater detail:

The term “theory” means a very different thing when used in everyday conversation and in science. In our day to day speech, we often use “theory” to mean a guess or unsubstantiated idea about how something works (as in “I have a theory that gremlins are hiding my car keys”).

In science, we would call such a guess a hypothesis, not a theory. A hypothesis is a proposed explanation for an observation. In this case, I am proposing that the explanation for why I can’t find my car keys is that gremlins are hiding them.

The distinction between the words “Theory” and “Hypothesis” is very important because in science “Theory” does not mean “guess”. I repeat, “Theory” does not mean “guess”.

According to the National Academies of Sciences, “some scientific explanations are so well established that no new evidence is likely to alter them. The explanation becomes a scientific theory. In everyday language a theory means a hunch or speculation. Not so in science. In science, the word theory refers to a comprehensive explanation of an important feature of nature supported by facts gathered over time. Theories also allow scientists to make predictions about as yet unobserved phenomena”.

People who don’t understand this distinction sometimes dismiss ideas saying “it’s just a theory” (this is very commonly used to suggest that evolution is just speculation, for example). But, when scientists speak of the theory of gravity or the theory of evolution, they don’t mean that these are random untested ideas that someone came up with after too many beers.

The AAAS (American Association for the Advancement of Science), the world’s largest scientific society, has this explanation of what scientists mean when they use the word “theory”:
” A scientific theory is a well-substantiated explanation of some aspect of the natural world, based on a body of facts that have been repeatedly confirmed through observation and experiment. Such fact-supported theories are not “guesses” but reliable accounts of the real world.”

Because of this crucial difference in meaning, I will ask students to use the word “hypothesis” whenever they are referring to a speculation or guess about how something works.

apes to manIt’s worth noting that based on this explanation, a scientist would reject The Curmudgeon’s theory on big baseball players, not because he thinks it’s untrue but because from his perspective, it’s a hypothesis, not a theory.

And The Curmudgeon has no problem with someone raining on his “big baseball players lose it faster” theory/hypothesis.

None of this, though, means that people need to accept theories like evolution or global warming – they should, because both are real and rejecting them means rejecting real, proven science – but people are entitled to make up their own minds. But when they decide they don’t believe in these theories, they should know first, that those theories are facts, not figments of someone’s imagination, and second, that writing them off because they’re “only” theories is as valid as stating that two plus three equals a bushel of potatoes.

Class dismissed.