science

Holden Karnofsky

Holden Karnofsky is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Holden Karnofsky rather than just read about it. In short: Holden G. Karnofsky (born 1980 or 1981) is an American nonprofit executive.

Key takeaways

Holden Karnofsky belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Holden Karnofsky to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Holden Karnofsky from memory before moving on to harder problems.

Reference excerpt

Holden G. Karnofsky (born 1980 or 1981) is an American nonprofit executive. Karnofsky co-founded the charity evaluator GiveWell with Elie Hassenfeld in 2007. In 2014, he co-founded the grantmaking organization Open Philanthropy (now called Coefficient Giving), and was its CEO and later co-CEO until 2023. He joined Anthropic in 2025.

Biography

Education and early career Karnofsky attended Stevenson High School in Lincolnshire, Illinois, and was named a National Merit Scholar. He graduated from Harvard University with a degree in social studies in 2003, splitting his studies particularly between economics, philosophy and psychology. At Harvard, he was a member of The Harvard Lampoon. After graduating, he worked at Bridgewater Associates, an investment management fund based in Westport, Connecticut.

GiveWell At Bridgewater, Karnofsky met his future GiveWell co-founder Elie Hassenfeld. In 2006, Karnofsky and Hassenfeld started a charity club where they and other Bridgewater employees pooled money and researched charities to determine where to direct money. In mid-2007, with donations from their colleagues, Karnofsky and Hassenfeld formed a fund called "The Clear Fund", and quit their jobs to work full time on GiveWell, whose goal was to allocate Clear Fund's money to the charities they assessed as most effective. In June 2012, GiveWell announced a partnership with Good Ventures, the philanthropic foundation tasked with giving away Facebook co-founder Dustin Moskovitz's wealth. Good Ventures has been one of GiveWell's main funders since then as well as a major donor to GiveWell-recommended charities. Annual donations to GiveWell-recommended charities increased from $1.6 million in 2010 to $110 million in 2015. Until 2023, he was vice chair of its board of directors.

Astroturfing incident In December 2007, Karnofsky was discovered posting a question about the organization to MetaFilter using another individual's name, and then posting an answer about GiveWell with his own name but without disclosing his affiliation with GiveWell. Karnofsky resigned as executive director after the incident and was later reinstated. The board cut $5,000 from his salary to pay for a professional development course he would be required to take. The incident had negative repercussions on GiveWell's reputation. Karnofsky's claim that the incident had been due to sleep deprivation and offer to donate to MetaFilter were mocked by users of the site.

Open Philanthropy Karnofsky was CEO and then co-chief executive officer of Open Philanthropy, a research and grantmaking foundation whose main funders are Cari Tuna and Dustin Moskovitz. Open Philanthropy is an outgrowth of GiveWell Labs, a collaboration of GiveWell and Good Ventures for more speculative giving. By August 2019, Open Philanthropy had made about 650 grants totaling $857 million to more than 370 organizations. In 2023, Karnofsky first took a leave of absence from his co-CEO role and then moved to a new role as Director of AI Strategy to focus on AI safety. In 2024, he became a Visiting Scholar at the Carnegie Endowment for International Peace. As of January 2025, he had left Carnegie. Karnofsky was on the board of directors of OpenAI between 2017 and 2021.

Anthropic Karnofsky joined Anthropic in January 2025 as a member of the technical staff, working on Anthropic's responsible scaling policies (a set of protocols to manage risks associated with increasingly powerful AI models) and other safety planning aspects.

Personal life In August 2017, Karnofsky married Daniela Amodei, who later co-founded Anthropic. They have a son. Karnofsky and Dario Amodei—Daniela's brother—were former roommates. Karnofsky is ethnically Jewish.

Views Karnofsky identifies with the effective altruism and has both represented and engaged with the movement. Earlier in his career, Karnofsky said he subscribed to a consequentialist moral framework that hoped to "give people more power to live the life they want to live". In recent years, he has written about the importance of extending empathy to all beings deserving of moral consideration, even when it is unusual or seems strange to do so. In a 2015 interview with Vox, Karnofsky said GiveWell should increase the racial and gender diversity of its staff and described steps the organization had taken. He has debated other nonprofit leaders on the importance of field visits, which he believes are important but not sufficient in evaluating the effectiveness of charitable programs. In August 2014, after the William and Flora Hewlett Foundation announced the end of its Nonprofit Marketplace Initiative (one of GiveWell's major early funders), Karnofsky wrote a post on the GiveWell blog offering his thoughts on the program, drawing on his experience as a grant recipient. The Hewlett Foundation responded in a comment on the post, and Jacob Harold, then GuideStar's chief executive, responded on the organization's blog. Karnofsky has shared his thoughts on altruistic career choice and elaborated on Open Philanthropy's approach to cause prioritization in an interview with Robert Wiblin for the 80,000 Hours podcast.

References

External links

Cold Takes - Karnofsky's blog

Illustrations

Worked examples

Example 1 — a first encounter with Holden Karnofsky

Start with the simplest possible case. Write down what Holden Karnofsky claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Holden Karnofsky before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Holden Karnofsky ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Holden Karnofsky

In research: Holden Karnofsky appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Holden Karnofsky in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Holden Karnofsky is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1980s births, AI safety advocates, American nonprofit businesspeople, so understanding it makes those chapters shorter.
In everyday life: Look for Holden Karnofsky outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Holden Karnofsky in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Holden Karnofsky means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Holden Karnofsky out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Holden Karnofsky in simple terms?

Holden G. Karnofsky (born 1980 or 1981) is an American nonprofit executive.

Why does Holden Karnofsky matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Holden Karnofsky?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Holden Karnofsky.