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- NEW: The Science-based Playbook for Effective Social Proof
NEW: The Science-based Playbook for Effective Social Proof
Grab it for $0, courtesy of Squarespace. 1 playbook, 36 practical recommendations to convert website visitors using social proof.
TL;DR: We partnered with Squarespace to turn the latest, most effective scientific evidence on how to boost your website conversions using social proof into a practical playbook. Download it (for free!) here.
Or first check out some of my favourite insights from the playbook below 👇
After 6 years of Science Says and many, many thousands of studies analyzed, some of what my team and I found here still surprised me.
I think you’ll love this.
You already have reviews, testimonials, and ratings on your website. The hard part is knowing which ones to show, and how.
For example (3 of the 36 recommendations in the playbook):
The reviews you should highlight are rated 4 to 4.5 stars, not 5. Products in that range outsell the ones rated 4.5 to 5.
Reviews containing a swear word were rated up to 37% more useful. Don't discard them, highlight them.
If you're new and don't have customers yet, say how many you expect to have. It increased inquiries by up to 20%.
None of these is a ‘growth hack’ or an opinion. Each one comes from a peer-reviewed, scientific study, carefully and manually vetted by our team of PhDs.
Everyone’s instinct when using social proof is to try to look as good as possible. But that’s not what works.
One of the 7 scientists my team and I interviewed for the playbook, Prof. Rebecca Wang from Lehigh University, puts it like this:
“When you approach social proof, don’t fall into the trap of making your business appear flawless.
The goal is to make people trust you. This means showing limitations, concerns, and clarifying who the product is not for.
A perfect five-star rating can actually work against you when consumers suspect that it was achieved by selectively soliciting or displaying positive feedback.”
But the evidence on how to do it right does exist. It’s just buried in academic papers like needles in a haystack.
So we teamed up with Squarespace to dig them out.
📘 Introducing: The Science-based Playbook for Effective Social Proof
My team and I reviewed thousands of studies on social proof and reviews, took the 45 that were the most high-impact and least used, and condensed 800+ pages of research into 36 practical recommendations.
I then went to 7 of the scientists behind the studies, from Oxford, Boston University, and Northeastern University, among others, to ask them for their recommendations on how to best apply their findings.
It covers three things:
Picking effective reviews. Which ones to handpick and showcase (see image below), and what the best ones should say.
Displaying reviews and social proof. How to show them so they feel credible, and what to show alongside them.
How to ask for effective reviews. What to ask, and when, down to the day of the week.

From the playbook: which reviews to feature
Plus: you’ll get a ready-to-use AI prompt that picks your best reviews for you (if you have thousands you need to sift through!).
⬇️ Get your free copy
It took my team and me months to put this together. It'll take you a few minutes to apply the first recommendation.
And it’s completely free 👇
Thomas
Founder, Science Says
P.S.: Want a preview of the playbook, or have any questions about it? On the 30th September, we’re doing a Squarespace Circle Live episode where I share some of my favorite insights, followed by a live Q&A. You can sign up here.
P.P.S.: Want your own science-based playbook like this in your area of focus? We regularly create science-based marketing, management, and AI insights for some of the best brands in the world, such as Squarespace, ServiceNow (example), or Wharton (example). Find out more here.