What is Identity and Personhood (⿻ identity)?

The idea of supporting how we show online that "I am me" not with a password, a single number or a fingerprint, but with the overlap of many people and organizations who can say "I know this person". The book Plurality argues this makes identity easier to establish and harder to spy on from one place.

When we sign up for an online service, we hand over an email address and a password, and sometimes a face photo or a fingerprint. It is convenient, but whoever holds that information — a company or a government office — may become able to see everything we do in one place. How can we show that we are who we are without being watched too closely? Identity and Personhood (⿻ identity) is the answer of the book ⿻ Plurality to this question.

In short

It is the idea of supporting how we show online that "I am me" not with a password or a single number or fingerprint, but with the overlap of many people and organizations who can say "I know this person" — schools, workplaces, friends, government offices and so on.

The book argues that this makes it easier to establish who you are, and at the same time harder for anyone to see everything from one place [1][2]. "Personhood" here means being recognized as a person.

For example

India's Aadhaar. Part of the Indian government's digital infrastructure, this system registers a photo, both irises (the pattern in the eye) and all ten fingerprints. More than 99% of the population has enrolled. The book rates it among the world's best in its mix of scale, inclusion and security. But it points out that when biometrics are used for everyday authentication, those running the system gain "an unprecedented capacity to surveil citizen activities across a wide range of domains". Activists have raised this concern in relation to India's Muslim minority. India's Supreme Court limited its use by the private sector [3].

Worldcoin. A global identity launched in 2019 by OpenAI co-founder Sam Altman and others, which scans irises with a device called the "Orb". The book criticizes it: using biometrics only for the first registration protects privacy, but makes the system "vulnerable to stealing or selling of accounts", and it cannot show anything beyond being a unique human [4]. For more, see the article on proof of personhood.

Social recovery. If you lose your key (something like a password), you can get it back if, for example, "3 of 5 friends or institutions" agree. The book notes that such "social recovery" has become "the gold standard in many Web3 communities" (Web3 being a vision of the internet built on blockchains) and "is increasingly being adopted even by major platforms such as Apple". It presents this as a way of recovering identity in the spirit of Plurality [5].

In more detail

The dilemma of proving versus protecting

Chapter 4-1 says that what an identity system is worth depends on how firmly it can establish who someone is. But the simplest ways of proving it (such as showing a password) create the danger of theft the moment they are shown. So, the book writes, in identity systems, protecting personal information is itself central to being useful, and systems should be judged by whether they can prove and protect at the same time [6].

Every kind of identity today has trade-offs

The book sorts today's identities like this [7]:

Government IDs are legitimate, but are reused in so many settings that they cannot be kept secret, and rest on thin information such as birth certificates.
"Sign in with…" from big tech companies is convenient, but a single company holds the whole picture of what we do.
Advertising and credit-scoring companies hold detailed information about us, but operate out of sight.
Small local identities (educational records, professional bodies, religious groups, names inside games and so on) feel natural and trustworthy, but are fragmented and hard to use.

There are also new identity technologies that do not rely on any particular company, but, the book writes, ways of managing keys without anyone's help, or recovering them when lost, are not yet established [8].

Identity as an "intersection"

The book's answer is to see people not as biological beings but as beings within society. When we think of someone, we think less of their face or body than of "things we did with the person, places we went together, things they did and ways they acted". The book calls this "sociometrics" (knowing people through social information) [9].

The book sums up the advantages of this approach in five points [9]:

Nothing is left out, and there are backups. With many relationships, losing one is not a problem.
Privacy. It only shares facts that people already know about each other, so it does not feel like being watched.
Confidence can be built up step by step. The more people vouch for you, the more certain it becomes.
No single point of weakness. Breaking one part does not bring down the whole.
Recovery. Separate groups of people who are unlikely to collude can together recover a lost identity.

How it would work

People are said to be able to maintain stable relationships with about 150 others (Dunbar's number). So, the book says, support is needed [10]. It names two forms. One places many mid-sized organizations that do the verifying. The other passes trust along chains of "friends of friends". The book works through a numerical example. Suppose 10 billion people each keep relationships with 100 potentially verifying institutions, and that for verification to work, any two people who meet must share at least 5 memberships. If memberships are randomly distributed, 300 verifiers could coexist while keeping the chance that verification fails for a random pair at one in several million. In reality, the book notes, people who meet are rarely random, nor are their affiliations, and 5 shared memberships are not always necessary, so many more verifiers could thrive. Yet the number would still be far smaller than the population, "perhaps around 100,000". It argues that combining the two forms could create an identity landscape that is both usable and private [10].

Identity is also a question of "association"

"Almost everything relevant about us is known by others and is typically just as much about them as us." So, the book says, what needs protecting is not so much hiding information as information remaining in the social setting for which it was intended — what the privacy scholar Helen Nissenbaum calls "contextual integrity" [11]. That means protecting the norms of groups, and so, the book concludes, "the central problems are about another fundamental right: the freedom of association" [11]. This leads into the next chapter, on ⿻ publics.

These ideas were developed before the book, in a series of blog posts by Glen Weyl and others (2019), and in a paper by Weyl, Puja Ohlhaver and Vitalik Buterin (2022) [12][13].

What is debated

Buterin's assessment. In his 2024 review, Vitalik Buterin, the founder of Ethereum, summed up the core of the book's view of identity as this: every method that relies on a single element is too weak, so many elements should be combined. On recovery mechanisms, he accepts that they are easy to understand, because each person chooses whom to trust, and a mistake affects only that person. But he points out that giving everyone the same amount of money, or voting, is harder, because it requires agreement about every member of the community [14].
The conflict over "one ID per person". World (formerly Worldcoin) argues that each person having only one credential is essential, and that allowing even a few multiple credentials would let them be bought and sold, opening a large hole [15]. Buterin, in contrast, wrote in 2025 that even if the contents are hidden with cryptography, trying to enforce one per person itself creates dangers — loss of privacy, coercion and mistakes — and that plural identity is the most realistic answer [16]. The book, too, criticizes the limits of biometric IDs that can show nothing but uniqueness [4].

Common misunderstandings

A common misunderstanding. ⿻ identity does not reject biometrics. When you meet someone you naturally see their face and so on, so social information can include biometric information; the book simply says it is not only that [9].

Where it fits in Plurality

This idea is the first detailed chapter (4-1) of Part 4 of the book. The book's chapter summary says: "The most fundamental of these rights is that to personhood, instantiated in digital identity systems that, from a ⿻, are grounded in many interesting social affiliations" [2].

In the picture of the rights operating system, identity corresponds to the "dots" (people). The next chapter's ⿻ publics are the "clusters around the dots" (associations), and the two are two sides of the same coin.

Many mechanisms later in the book rely on this kind of identity: for example ⿻ Voting, which takes people's connections into account, and Social Markets, which trace who has a stake in what. The part that shows "being one unique human" is covered in proof of personhood.

Sources

Plurality, 4-1 "Identity and Personhood", opening — https://www.plurality.net/v/chapters/4-1/eng/ ［CC0］
Plurality, chapter summaries (Chapter 4-1) — https://github.com/pluralitybook/plurality/blob/86158859464aee75633acd854c656928121a7fd8/contents/english/8-blurb.md ［CC0］
Plurality, 4-1, section "Public and decentralized digital identity" (Aadhaar) — https://www.plurality.net/v/chapters/4-1/eng/ ［CC0］
Plurality, 4-1, section "Public and decentralized digital identity" (Worldcoin) — https://www.plurality.net/v/chapters/4-1/eng/ ［CC0］
Plurality, 4-1, section "Identity as an intersection" (Recovery) — https://www.plurality.net/v/chapters/4-1/eng/ ［CC0］
Plurality, 4-1, second and third paragraphs of the opening — https://www.plurality.net/v/chapters/4-1/eng/ ［CC0］
Plurality, 4-1, section "Digital identity today" — https://www.plurality.net/v/chapters/4-1/eng/ ［CC0］
Plurality, 4-1, second half of "Public and decentralized digital identity" — https://www.plurality.net/v/chapters/4-1/eng/ ［CC0］
Plurality, 4-1, section "Identity as an intersection" — https://www.plurality.net/v/chapters/4-1/eng/ ［CC0］
Plurality, 4-1, section "⿻ identity" — https://www.plurality.net/v/chapters/4-1/eng/ ［CC0］
Plurality, 4-1, section "Identity and association" — https://www.plurality.net/v/chapters/4-1/eng/ ［CC0］
Weyl, Geiger and Young, "Motivating The Case for Decentralized Social Identity" (2019) — https://www.radicalxchange.org/updates/blog/2019-06-06-d4utdx/ ; "Intersectional Social Data" (2019) — https://www.radicalxchange.org/updates/blog/2019-10-24-uh78r5/
Ohlhaver, Weyl and Buterin, "Decentralized Society: Finding Web3's Soul" (2022) — https://papers.ssrn.com/sol3/papers.cfm?abstract_id=4105763
Vitalik Buterin, "Plurality philosophy in an incredibly oversized nutshell", section on identity (2024-08-21) — https://vitalik.eth.limo/general/2024/08/21/plurality.html
World white paper, "Achieving Proof of Human" — https://whitepaper.world.org/achieving-proof-of-human
Vitalik Buterin, "Does digital ID have risks even if it's ZK-wrapped?" (2025) — https://vitalik.eth.limo/general/2025/06/28/zkid.html

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