Think you know stock photos?

Think again.

Like most people, you probably don’t overthink your blog images. Once you find a relevant photo, you probably just stick with it.

However, your choices might be hurting your conversion rate.

Even with my background in psychology, I’m always flabbergasted how small—seemingly irrelevant—changes can make a big impact.

…and that goes for your stock photos as well.

In this article, I pull from academic research to explain the persuasive impact of images. In particular, I explain how stock photos can influence your perception and behavior without your conscious awareness.

More importantly, you’ll learn which stock photos can trigger a desire to convert (and why).

Let’s dive in…

Click to download a PDF version of this post.

Three Types of Conversions

All the recommendations in this article are based on priming. To give you a better understanding, I recorded this quick video:

In that video, I explained how images can prime concepts in your semantic network (which can then influence your perception and behavior).

…and that’s the key to choosing stock photos.

You should strategically choose your images based on the associations that they will activate (and you should activate concepts that will trigger a desire to convert).

Which concepts will trigger a desire to convert? It depends on your niche.

Certain niches have certain types of conversions. When choosing a concept to prime, you need to choose a concept that’s conducive for your type of conversion.

After scouring the academic literature, I chose to separate the recommendations into three conversions:

  1. Rational Conversions – People convert from a logical standpoint (e.g., people subscribe to a software blog to receive useful tips)
  2. Emotional Conversions – People convert from an emotional standpoint (e.g., people subscribe to a fashion blog to stay updated on the latest trends)
  3. Prosocial Conversions – People convert from a moral standpoint (e.g., people donate to a Kickstarter campaign or charity)

The remainder of the article will give you suggested images for each type of conversion.

Note: Some of these suggestions will seem bizarre. In fact, a lot of these suggestions will seem bizarre. I tried to ease the bizarreness by including an academic research study to back up each claim.

Rational Conversions

When people convert from a rational standpoint, you should prime people’s concept for rationality. Once those associations become activated in their semantic network, they’ll be more likely to notice and appreciate the rational benefits of converting.

Here are some images that can help:

a. Brain Images from MRI or fMRI

Not just any brain image…it’s important that you show brain images from an MRI or fMRI. You’ve seen these images before:


Don’t underestimate them. Those images possess a magical quality.

In one study, researchers found that those brain images (compared to other brain images, bar graphs, and no image) influenced people to perceive a scientific article to be more credible (McCabe & Castel, 2008).

The researchers concluded:

“These data lend support to the notion that part of the fascination, and the credibility, of brain imaging research lies in the persuasive power of the actual brain images themselves.”

When you use an image of a brain (especially an image from an MRI or fMRI), you’ll trigger associations with analytical thinking. Once that concept becomes activated, your visitors will develop a stronger appreciation for the rational benefits of converting (and they’ll also view your content to be more credible).

b. Business-Related

Your concept of “business” has many associations, such as competitiveness and selfishness.

Researchers found that those associations can influence your perception and behavior. For example, Kay et al. (2004) found that exposing participants to business-related stimuli (e.g., briefcases, dress shoes, fountain pens) caused people to behave more competitively.

If your conversion provides people with a rational set of benefits, priming their concept of business will trigger a “what’s-in-it-for-me” mindset, which should help them appreciate the rational benefits of converting.

Luckily, stock photos are known for their cliche business images:

Are they clapping at a blank screen?
Bet they’re watching Nyan Cat.
Is it just me…or does this one look seductive?

c. Asian Males

It sounds crazy, but let me explain.

Just like other concepts in our semantic network, gender and race are associated with certain qualities and characteristics. Even if we don’t believe in those stereotypes, the mere existence of those associations can influence us.

Shih, Pittinsky, & Ambady (1999) examined that question using a group of people who belonged to conflicting stereotypes: Asian-American women.

  • On one hand, there’s a stereotype that Asians are superior at math.
  • On the other hand, there’s a stereotype that women are inferior at math.

Before giving them a math test, the researchers asked them questions:

  • Some were asked questions about their race (e.g., the languages they spoke at home).
  • Some were asked questions about their gender (e.g., if the floors in their dorm were co-ed)

What happened? You guessed it. Those questions primed the corresponding stereotypes. People who were asked questions about their race performed better, whereas people who were asked questions about their gender performed worse.

Asian Priming Study Results

How does that finding relate to conversions?

When you want people to appreciate the rational benefits of converting, you can take advantage of that stereotype.

Since the stereotype of “Asian” is usually associated with superior analytical skills, you can use images to prime that association. Since the stereotype of “men” is usually associated with more rational thinking, showing images of that gender should also trigger greater reliance on rationale.

You may have thought the featured image was a teaser, but if your conversions are based on rationality, then the image of the Asian male might be your best bet.

Bonus points for the business suit (Kay et al., 2006)

As we’ll see later, that photo still isn’t ideal. In fact, none of those photos are ideal. All three images might actually hurt your conversion rate. I’ll give you a few paragraphs to think about the reason why.

Emotional Conversions

When your conversions are based on emotion, you should be priming a different set of associations. Rather than prime rationality, you should prime concepts that will influence people to use their emotion when deciding to convert.

Here are some images that can help:

a. Whimsical Cuteness

In a recent study, Nenkov & Scott (2014) presented people with different Amazon gift cards and asked them to choose from a list of movies to purchase.

  • Some movies were low brow (e.g., Bridesmaides, Hangover II, Ted)
  • Some movies were high brow (e.g., The King’s Speech, The Help, Jane Eyre)

Take a guess. Which gift card below (recreated by me) made people more likely to choose low brow movies:


Give up? It was Gift Card A, with the circular designs.

The researchers found that “whimsically cute” designs can prime concepts of fun, which will make people more likely to indulge in rewards (e.g., by choosing low brow movies).

But how come the baby didn’t make people more likely to indulge? Wouldn’t that image also prime the idea of fun and lightheartedness?

Not quite. As the researchers explained:

“…exposure to a cute baby leads to automatic trait inferences of “vulnerable” and “caretaking,” which should not increase indulgence in subsequent behavior.”

In fact, other researchers have found a negative effect from baby images. Since images of cute babies can trigger the concept of caretaking, they can make people less likely to indulge—and more likely to do the “responsible” thing (Sherman, Haidt, & Coan, 2009).

When your conversion involves an emotional decision (or if your niche involves some type of indulgence), you should incorporate whimsically cute designs into your website. Those images will prime the concept of “fun,” making people more likely to indulge.

…and make sure to avoid images of babies.

b. Smiling People

When people are in a happy mood, they’re more likely to base decisions on emotion. That positive mood creates a sense of naive optimism. We falsely assume that information must be accurate, so we don’t spend as much time rationalizing.

How can you trigger that positive mood? Show images of people smiling.

Murphy and Zajonc (1993) subliminally flashed smiling or frowning faces to a group of participants. Even though participants weren’t aware of that exposure, they evaluated stimuli more favorably after being exposed to the happy faces.

That principle takes advantage of the chameleon effect (Chartrand & Bargh, 1999). When we’re exposed to nonverbal behavior, we experience an unconscious urge to mimic that behavior (and that subtle mimicry instills that same emotion within us).

In fact, the chameleon effect can explain the question I asked earlier. Do you know why the images of the three people could hurt your conversion rate? It doesn’t involve smiling (although I should award even more bonus points to Person C who is smiling):


Look at their body language. What are they doing? They’re crossing their arms.

Uh oh.

Within our schema for “crossing arms,” we usually associate the idea of closed-mindedness. In fact, Friedman and Elliot (2008) found that people were able to solve more anagram puzzles when they were coerced into crossing their arms (because it triggered a persistent attitude).

When you expose images of people crossing their arms, you subconsciously prime people to become more unyielding (Bull, 1987), which will make them less likely to convert.

Given that circumstance, it’s funny how common that pose has become in stock photos. When choosing your images, pay careful attention to the body language of the models. Choose images where people aren’t crossing their arms.

c. People Looking Toward Your CTA

This suggestion will work with any type of conversion, but it will have the strongest impact with emotional conversions.

In order to trigger a desire to convert, you should position people in stock photos so that they are facing your CTA.

You might have seen this heatmap before:

Source: Tobii

The content to the right of the baby received much more attention after positioning the baby toward it (rather than facing the website visitors).

Source: Tobii

But why does that occur?

Turns out, we have a natural, inborn tendency to follow people’s gazes. That tendency was an evolutionary trait that helped us learn about the world, and it’s still ingrained in our amygdala (see Emery, 2000 for an in-depth review).

By positioning people in stock photos toward your CTA, your website visitors will be naturally drawn toward those areas (and they will have a stronger desire to convert).

Why will they have a stronger desire?

Although the increased attention is due to gaze following, the increased desire is due to processing fluency (Alter & Oppenheimer, 2009). I explain that principle in this post, as well as in Methods of Persuasion.

Prosocial Conversions

What if your conversions are based on prosocial behavior, such as donating? Since those conversions lead to both emotional and rational reasoning, what types of associations should you prime?

Here are some ideas.

a. Make People Self-Aware

By the end of this section, you’ll understand why images of people pointing can influence people to act more ethically.


The answer involves self-awareness.

When we’re focused on ourselves, we experience a negative discomforting feeling (Mor & Winquist, 2002). The feeling is so small that we’re usually not aware of it.

Nonetheless, that altered state is enough to influence our behavior. How? When we experience that discomfort, we try to overcome it by acting in a responsible, moral, or socially encouraged manner (Gibbons, 1990).

For example, one of my past professors examined self-awareness in trick-or-treaters. Her team found that children were less likely to steal candy when a mirror was present behind the bowl. Why? The mirror primed the children’s self-awareness, which extracted more responsible behavior from them (Beaman et al., 1979).

If your conversion involves prosocial behavior, you can prime people’s self-awareness with the following images:

Images of Eyes

Just like mirrors, eyes can also prime self-awareness.

In one study, Bateson et al. (2006) provided customers with an unsupervised “honesty box” to pay for their lunch. Over the course of 10 weeks, the researchers showed different banners behind the counter: either a flower or a pair of eyes. Surprisingly, when images of eyes were displayed, the researchers received 3x more money.

Although eyes can be effective, they might be difficult to fit naturally into your content.

Let’s face it…they’re pretty creepy:

Yep. That’s me staring into your soul.

The next idea can achieve the same outcome in a more subtle way.

Images of Pointing

Now that you understand self-awareness, the image from the beginning of the article might make more sense.

In addition to eyes, images of people pointing outward should also trigger self-awareness:


Although I can’t find a study using that type of image, I would venture a guess that those images might even be more effective than eyes.

b. Avoid Business and Money

For rational conversions, I explained how people usually associate the concept of “business” with a “what’s-in-it-for-me” mindset.

If your conversion is prosocial, you should avoid incorporating business-related images because they can make people more selfish (Kay et al., 2006).

The same effect occurs with money. Researchers found that people act more corrupt when they are primed with the concept of money (Kouchaki et al., 2013).

So what concept should you prime? Besides self-awareness, another association that would help is religion.

c. Religious Images

Much like business, religion can trigger certain associations—namely, moral and ethical behavior.

In one study, people who were exposed to words related to God (e.g., spirit, Divine, God) showed more ethical behavior in an economic game (Shariff & Norenzayan, 2007).

Also, you don’t need to be religious to be influenced by those images. Just like with stereotypes, the mere existence of those associations is enough to trigger moral behavior. In fact, the outcome from the previous study also influenced Atheists—people who aren’t religious at all.

Whether you include images related to religion (e.g., crosses) or you end your written signature with a “God Bless,” those exposures will make people more likely to complete your prosocial conversion.


Will the suggestions in this article give you a huge boost in conversions? Probably not.

My main focus in writing this article was explaining the underlying science behind those suggestions. I’m hoping that this article at least made you think of stock photos differently.

Next time you’re choosing an image, just think about the associations that you might be priming. Always choose images that will prime helpful concepts for your type of conversion.

To help reinforce that main idea, I created this summary table:


Final Thoughts

There’s a funny thing about priming. The effects only occur when you’re unaware that they’re happening.

If you realize that someone is trying to influence you, a “reverse priming effect” occurs (Laran, Dalton, & Andrade, 2011). You react against that persuasion attempt, and you become less likely to be persuaded.

That said, it’s always tough ending a post about influence and persuasion with a CTA. If I do one of the strategies, then I’ll look like a slimeball 🙂

But you enjoyed this post, then you’d also enjoy my book, Methods of Persuasion. I explain a ton of other practical strategies that you can implement online.

Or if you’re not ready to pick up a copy of the book, you can subscribe to my blog to stay updated on new content.