While many of us want to believe we make all our purchasing decisions based on cold, hard logic, there is no doubt that emotions can play a role in what we ultimately end up choosing. In fact, back in the 1970s, Daniel Kahneman and Amos Tversky found that humans regularly make decisions that defy logic. Much of that has to do with people being emotional creatures. For entrepreneurs, marketers and others who seek to influence people's decisions, tapping into these emotions is a powerful tool.

A new study from Tillburg University in the Netherlands, which was published in the journal "Social Psychological and Personality Science" suggests that people mirror the emotions of others they see online and also seek out other people who share our emotions.

Researchers reviewed more than 2,000 video blogs on YouTube for their study. To be included, the video blogs, or vlogs, had to have at least 10,000 subscribers. Some of them had millions.

What the researchers were looking for is called "contagion," the act of being affected by other people's emotions, and "homophily," the act of seeking out other people who have similar outlooks and moods.

Vloggers on YouTube often share personal stories that can conjure a range of emotions and the researchers wanted to see how those emotions affected viewers. They did this by analyzing the language of the comments related to each video to see what emotions viewers had while watching the videos.

They then tracked and modeled the emotional reactions of viewers, both for contagion and homophily and found that there was an immediate and sustained emotional effect on viewers.

A positive video garnered generally positive emotions while videos that displayed other types of emotions generally had comments that mirrored the emotions on display in the video. It is likely a combination of contagion, sympathy and empathy that causes people to mirror the emotions they see, the researchers said in a press release.

Although this study targeted vlogs on YouTube and the viewers of those vlogs, it has valuable lessons for anyone who wants to influence people, like these three takeaways.

1. You need to back up your numbers.

Numbers are great for setting, measuring and achieving goals, but outside of hardcore math fans, they aren't compelling and they can only tell half of any story. No matter how much your product or service increases X or decreases Y, those cold, hard digits alone will rarely sway people.

You need to hit customers, clients, investors, etc. with something more than just numbers, something that will trigger that coveted emotional response.

In our drug testing business, we know that what we are selling is not drug test results. Rather, we are giving people peace of mind, whether that's helping a loved one get over addiction or hiring employees who do not have issues with drugs. Our customers do not really care if there are six or 16 drugs being tested for on a urine panel. They just want the comfort that comes with drug testing.

2. You don't necessarily need to tug on heartstrings.

There are as many emotional connections to make with people as there are emotions, which is to say; a lot. You can make people laugh, cry, get angry, scared or worried. Whatever emotion you are going for, as long as it relates to what you're selling, is better than not making that connection.

The emotions you want to tap into can be different for various customer segments or they can be approximately the same for all of them. With our drug tests, it is the aforementioned peace of mind that we are trying to get all of our customer segments to feel.

For employers who want to avoid major catastrophes at work as a result of drug use, parents who want to help their kids avoid addiction and anyone who is helping a loved one overcome addiction, we offer that aforementioned peace of mind.

Soda companies try to get people to associate their products with fun and good times while sports apparel companies often try to get people to feel like they can accomplish anything if they are wearing that particular apparel.

3. You don't have to do it with video, but that's probably best.

As the researchers point out, there have been other studies that have examined contagion and homophily in written contexts like Twitter and Facebook, but this was the first one done using a video based social media site like YouTube.

Video has myriad advantages for conveying an emotion that you just cannot get with the written word or even an image. Imagine the power of seeing an employee under the influence of drugs causing an accident as opposed to just reading about it.