As it's nearly Valentine's Day, it's a good time to feature this new story on so-called "love languages." According to a new review by relationships researchers, it looks like we should lump this idea, along with the Myers Briggs Type Inventory and learning styles, into the category of "things that make research psychologists cringe."

Many journalists have covered an empirical review article recently published in the journal, Current Directions in Psychological Science. by psychologists. This post features an story for the website medical express.

Even if you don't know your love language, you've probably heard of the concept. The theory's pervasiveness in pop culture has only increased in the 30-odd years since Baptist pastor Gary Chapman published his book "The Five Love Languages: The Secret to Love That Lasts." […]

"We were very skeptical about the love languages idea, so we decided to review the existing studies on it," says Emily Impett, a professor in the UTM department of psychology who collaborated with UTM graduate student Gideon Park and York University Assistant Professor Amy Muise. "None of the 10 studies supported Chapman's claims."

Chapman's book argues that there are five love languages: physical touch, words of affirmation, acts of service, quality time and gifts, and that each person has a primary preference for one of them. Furthermore, he argues in his book that when two partners have the same love language (for example, both of them prefer physical touch) that their relationship will be better.

The journalist explains that Impett and her team tested each of Chapman's ideas. One was that people only have one primary love language. In fact, Chapman's unscientific "quiz" forces people to choose one. When people are provided a likert scale for each type, they report multiple preferences of showing and expressing love. Second, Chapman's original thinking was based on a restricted sample (mostly White, religious, middle-class Americans), and in other cultural contexts, there may be different ways of expressing love. 

But let's focus on this claim:

Most importantly, Impett and her team found no scientific evidence for Chapman's central contention that people who choose partners that speak their love language, or learn to speak it, will have more successful relationships. "There's no support for this matching effect," says Impett. "People are basically happier in relationships when they receive any of these expressions of love." 

The researchers reviewed the literature and found

no scientific evidence for Chapman's central contention that people who choose partners that speak their love language, or learn to speak it, will have more successful relationships. "There's no support for this matching effect," says Impett. "People are basically happier in relationships when they receive any of these expressions of love." 

This conclusion is a great example of the theory-data cycle. Let's walk through it. I've included Figure 1 for your reference.

a) The theory-data cycle starts with a theory. What is Chapman's theory about love languages? Remember that a theory is a series of general statements about how variables are related to each other. 

b) A researcher can then design a study to test the theory. In one study that Impett and her team reviewed, researchers recruited a sample of couples and measured each person's love language, and also measured their relationship satisfaction. Then they divided the couples into two types: those who had the same love language and those that did not. 

c) The next step in the theory-data cycle is to state a hypothesis for the study–what should the results of this specific study be if the theory is true? Sketch a graph of the predicted outcome, or state specifically what the results should be. 

d) The next step is to evaluate the results in light of the theory. What did the study actually find? Do these results support the theory, or not?