---
title: "Authority, liking, scarcity and unity | Optimize All Academy"
description: "Four more principles This lesson covers the remaining principles — authority, liking, scarcity and unity — with ethical applications and red lines. 4…"
url: https://optimizeall.com/learn/sales-psychology-and-persuasion-ethics/authority-liking-scarcity-unity
updated: 2026-10-05
---

Sales Psychology & Ethical Persuasion · Cialdini's principles, applied ethically · lesson 5 of 14 · 14 min

# Authority, liking, scarcity and unity

## Four more principles

This lesson covers the remaining principles — **authority, liking, scarcity and unity** — with ethical applications and red lines.

## 4. Authority

**What it is**: people tend to follow credible experts.

**Ethical use**: demonstrate genuine expertise and cite credible sources accurately.

- Share how you tested a product, your relevant qualifications or experience.
- Reference genuine expert guidance (for example, a dermatologist's general advice on sunscreen) accurately and in context.
- Be clear about the limits of your expertise: "I'm not a doctor — if you have a skin condition, see one."

**Where it crosses the line**:
- Claiming credentials you don't have, or wearing a lab coat to imply medical authority.
- "Doctors recommend" or "clinically proven" without substantiation.
- Presenting paid experts as independent without disclosure.

## 5. Liking

**What it is**: people are more easily influenced by people they like — those who are similar, friendly, complimentary and cooperative.

**Ethical use**: be genuinely yourself, find real common ground, be warm and helpful.

- Share relatable experiences and your real personality.
- Engage personally with your community.
- Compliment sincerely — never as a tactic.

**Where it crosses the line**:
- Faking similarity ("I'm also a struggling student!" when you're not).
- Love-bombing: excessive flattery to lower defences before a pitch.
- Using parasocial relationships to pressure: "If you really supported me, you'd buy this."

## 6. Scarcity

**What it is**: things seem more valuable when they're rare, limited or at risk of being lost.

**Ethical use**: communicate *genuine* limits clearly — real stock limits, real deadlines, seasonal availability.

- "The brand's Eid discount ends Friday at midnight Gulf time."
- "This is a limited-edition run — the brand has confirmed no restock."

**Where it crosses the line**:
- Fake countdown timers and "only 2 left" when untrue — widely treated as misleading by regulators, including the UK CMA, the US FTC and EU consumer authorities.
- "Price goes up tomorrow" when it doesn't.
- Creating panic to stop people comparing options.

**Framing tip**: loss framing ("don't miss out") is more intense than gain framing ("get this benefit"). Use loss framing sparingly and only when the loss is real.

## 7. Unity

**What it is**: people are influenced by those they see as part of a shared identity — "one of us" — such as family, community, region, faith or a shared passion.

**Ethical use**: build genuine community around shared values and interests.

- A modest-fashion community sharing styling ideas for Eid.
- A local creator championing businesses from their city.
- A running community where members encourage each other.

**Where it crosses the line**:
- Exploiting identity to shut down scrutiny: "Real Muslims / real Pakistanis / true fans buy this."
- Using religious or national sentiment to sell products with no genuine connection to it.
- Creating "us vs. them" hostility towards competitors or critics.

Identity-based appeals are powerful and sensitive — especially around faith and nationality. Use them only when the connection is genuine and respectful.

## Putting it together: an ethical campaign example

A UK-based Pakistani creator promotes a halal-certified skincare brand to her community:

- **Authority**: she shares the certification details and her testing process; she notes she isn't a dermatologist.
- **Liking**: she films in her real bathroom, sharing her own routine.
- **Scarcity**: she mentions the brand's genuine launch discount, with the actual end date.
- **Unity**: she speaks to her community's genuine desire for halal-certified options — without implying anyone who doesn't buy is less devout.

Every principle is at work; every one passes the truth, transparency, benefit and freedom tests.

## Do and don't

**Do** show real expertise and its limits. **Do** be genuinely yourself. **Do** communicate real deadlines and stock limits. **Do** build genuine community.

**Don't** fake credentials, similarity or scarcity. **Don't** use parasocial guilt. **Don't** weaponise faith or national identity.

## Evidence notes

- **Authority:** Milgram's obedience experiments (1960s) are often cited to show deference to authority; they're influential but debated (including critiques of how the studies were run and reported), and they're about obedience, not buying. For sellers, the practical point is simpler and uncontroversial: people rely on credible expertise, so fake credentials are especially harmful.
- **Scarcity:** a classic 1975 study (Worchel, Lee and Adewole) found that cookies from a nearly empty jar were rated more desirable than identical cookies from a full jar. Scarcity effects are widely observed, but regulators specifically target *false* scarcity, and fake urgency is one of the most commonly cited dark patterns.
- **Liking and unity:** similarity and shared identity reliably increase trust; they are also the principles most easily abused through parasocial pressure and identity politics.

## Current rules on scarcity and urgency

- **UK:** the CMA's consumer-enforcement powers (since April 2025) cover misleading urgency and pressure selling; it opened its first investigations under those powers in November 2025, including into online pricing practices.
- **EU:** the UCPD blacklist includes falsely stating that a product will only be available for a very limited time to elicit an immediate decision.
- **US:** the FTC's 2022 dark-patterns report lists fake countdown timers and false low-stock messages as deceptive.

## Hands-on: an authority and scarcity claims register

Keep a simple register for every campaign:

| Claim | Type | Evidence held | Who confirmed | Expiry / review date |
|---|---|---|---|---|
| "Dermatologist-tested" | Authority | Test report ref., date | Brand regulatory team | Re-check each campaign |
| "Offer ends Friday 23:59 GST" | Scarcity (time) | Brief, section 3 | Brand manager (email) | Friday |
| "Limited edition — 500 units" | Scarcity (stock) | Production confirmation | Brand | Until sold out |
| "Used by 3 NHS trusts" (B2B) | Authority/social proof | Client permissions on file | Legal | Annual |

If a claim has no evidence in the register, it doesn't go out.

## Before and after: a unity appeal

**Before:** "Every proud Pakistani should support this brand — real patriots buy local!"

**After:** "This brand is made in Sialkot by a family business I've visited, and I love that. Here's what I like about the product and one thing I'd improve — buy it if it suits you."

The first uses identity to shut down scrutiny; the second shares a genuine connection and leaves the choice open.

## Measuring

Track complaints mentioning "misleading", "fake" or "pressure"; refunds within the cooling-off period; and, for B2B, whether references and case studies are actually requested and used by buyers. Genuine authority and social proof get checked — and pass.

## Video lecture: Authority, liking, scarcity and unity

Lecture coming soon · 12 chapters · about 9 minutes. Read the full transcript below.

1. Authority, liking, scarcity, unity
2. Why these four
3. Authority
4. Liking
5. Scarcity
6. Unity
7. Example 1: unity appeal
8. Example 2: Ben, London (illustrative)
9. Watch me do it: claims register
10. All four, honestly
11. Mistakes + measures
12. Recap + try this now

## Lecture transcript

### Authority, liking, scarcity, unity

A man in a white coat recommends a supplement. A creator you've followed for years says, if you really supported me, you'd buy this. A banner says only two left. And a caption says, every true fan buys this. Four principles of influence, used four questionable ways. In this lecture you'll learn authority, liking, scarcity and unity: how each works, how to use each honestly, where each crosses the line, what the evidence and current regulations say, and a claims register that keeps you on the right side.

### Why these four

Why group these four? Because they're the principles most tied to who you are and how you present yourself: your expertise, your personality, your offers and your community. That makes them powerful, because people trust people. And it makes them dangerous, because abuse feels personal when it's discovered. A fake credential or a guilt trip doesn't just lose a sale. It turns a follower or client into someone who warns others.

### Authority

Authority first: people tend to follow credible experts. Ethical use means showing genuine expertise and citing credible sources accurately. Share how you tested a product. Mention relevant qualifications or experience. Reference genuine expert guidance in context. And be clear about your limits: I'm not a doctor; if you have a skin condition, see one. The red lines: claiming credentials you don't have; wearing a lab coat to imply medical authority; saying doctors recommend or clinically proven without substantiation; and presenting paid experts as independent. A note on evidence: Milgram's obedience experiments are often quoted here, but they're debated and they're about obedience, not buying. The simpler point stands on its own: people rely on credible expertise, so fake expertise does special harm.

### Liking

Liking: people are more easily influenced by people they like, who are similar, friendly and cooperative. Ethical use is simply being yourself: sharing relatable experiences, engaging personally with your community, complimenting sincerely. The red lines: faking similarity, like I'm also a struggling student when you're not; love-bombing, meaning excessive flattery to lower someone's defences before a pitch; and using parasocial relationships to pressure people: if you really supported me, you'd buy this. That last one is increasingly common among creators, and it's corrosive. Your audience's affection is a gift, not a lever.

### Scarcity

Scarcity: things seem more valuable when they're rare, limited or at risk of being lost. A classic nineteen seventy-five study found that cookies from a nearly empty jar were rated more desirable than identical cookies from a full one. Scarcity effects are widely observed, which is exactly why regulators target false scarcity. The UK Competition and Markets Authority can now fine directly for misleading urgency and pressure selling. The EU's consumer rules blacklist falsely claiming a product is available only for a very limited time. The US Federal Trade Commission lists fake countdown timers and false low-stock messages as deceptive. Ethical use: communicate genuine limits only. The brand's Eid discount ends Friday at midnight Gulf time. This limited edition won't be restocked, confirmed by the brand.

### Unity

Unity: people are influenced by those they see as part of a shared identity: family, community, region, faith or a shared passion. Ethical use means building genuine community around shared values: a modest-fashion community sharing Eid styling ideas, a local creator championing businesses from their city, a running club where members encourage each other. The red lines: exploiting identity to shut down scrutiny, like real Muslims or true Pakistanis buy this; using religious or national sentiment to sell products with no genuine connection to it; and creating us-versus-them hostility towards competitors or critics. Identity appeals are powerful and sensitive, especially around faith and nationality. Use them only when the connection is genuine and respectful.

### Example 1: unity appeal

First example, the simple one: a unity appeal. Before: every proud Pakistani should support this brand; real patriots buy local! After: this brand is made in Sialkot by a family business I've visited, and I love that. Here's what I like about the product, and one thing I'd improve. Buy it if it suits you. The first uses identity to shut down scrutiny: if you don't buy, you're not a real patriot. The second shares a genuine connection, gives honest information and leaves the choice open. Both mention national pride. Only one respects the viewer.

### Example 2: Ben, London (illustrative)

Now a realistic business scenario, with illustrative details. Ben sells cybersecurity services in London to hospitals and clinics. His pitch deck claims the firm is trusted by the NHS, in large type. In fact, two NHS trusts are clients, and only one has agreed to be named. That's authority and social proof overstated. His deck also says the offer ends Friday, when the price is the same next quarter. False scarcity. He fixes both. The deck now says: working with two NHS trusts, one of which is happy to take reference calls. And the scarcity becomes genuine: we have capacity for two new implementations this quarter. Illustratively, a procurement lead later tells him the named reference was the deciding factor.

### Watch me do it: claims register

Watch me do it. I'll fill in the claims register from the lesson for a skincare campaign in the UAE. Claim one: dermatologist-tested. Type: authority. Evidence: I ask the brand for the test report reference and date. They send it. Confirmed by the brand's regulatory team. Re-check each campaign. Claim two: offer ends Friday at eleven fifty-nine p.m. Gulf time. Type: scarcity. Evidence: section three of the brief. Confirmed by the brand manager by email. Claim three: limited edition, five hundred units. Evidence: the brand can't confirm the number. So claim three doesn't go out. The rule is simple: no evidence in the register, no claim in the content.

### All four, honestly

Here's how all four principles can work together honestly. A UK-based Pakistani creator promotes a halal-certified skincare brand to her community. Authority: she shares the certification details and her testing process, and says clearly that she isn't a dermatologist. Liking: she films in her real bathroom, showing her own routine, unpolished. Scarcity: she mentions the brand's genuine launch discount, with the actual end date the brand confirmed in writing. And unity: she speaks to her community's real desire for halal-certified options, without implying that anyone who doesn't buy is less devout. Every principle is at work. Every one passes the truth, transparency, benefit and freedom tests.

### Mistakes + measures

Common mistakes. Borrowed authority: implying expertise you don't have. Parasocial guilt. Countdown timers that reset. Scarcity claims you haven't confirmed in writing. Faith or national identity used to sell unrelated products. And big-name logos you're not entitled to use. How to measure: track complaints that mention words like misleading, fake or pressure; refunds within the cooling-off period; and, for business sales, whether buyers actually request and use your references and case studies. Genuine authority gets checked, and passes.

### Recap + try this now

Recap. Authority: show genuine expertise and its limits, never fake credentials or unsupported claims. Liking: be yourself; no faked similarity, love-bombing or parasocial guilt. Scarcity: only real, confirmed limits, which regulators increasingly police. Unity: build genuine community, never weaponise faith or identity. Your try-this-now action: create a claims register for your next campaign or proposal, and drop any claim without evidence. Next, we'll look at the cognitive biases that shape buying decisions.

## Key takeaways

- Authority: show genuine expertise and its limits; never fake credentials or claims.
- Liking: be authentic — no faked similarity, love-bombing or parasocial guilt.
- Scarcity: communicate only real limits and deadlines.
- Unity: build genuine community; never weaponise faith or identity.

## Try it

Take one of your recent campaigns and write how each of the seven principles appears — then flag and fix any use that fails the four ethical tests.

- [Previous: Reciprocity, commitment and social proof](https://optimizeall.com/learn/sales-psychology-and-persuasion-ethics/reciprocity-commitment-social-proof)
- [Next: Cognitive biases in buying decisions](https://optimizeall.com/learn/sales-psychology-and-persuasion-ethics/cognitive-biases-in-buying)
- [All lessons of Sales Psychology & Ethical Persuasion](https://optimizeall.com/learn/sales-psychology-and-persuasion-ethics)