Not Invented Here (NIH)
External ideas discounted — only what we built ourselves counts as real
In-group origin is mistaken for merit; outside knowledge is treated as suspect, incomplete, or not invented for us — regardless of tier.
Not Invented Here (NIH) is the bias that ideas, tools, and evidence from outside the boundary are automatically downgraded — another team’s library, a vendor proposal, an acquired company’s practice, a published method from another industry. The organisation prefers to rebuild, rebrand, or rediscover rather than adopt, even when external tier is higher and cost of reinvention is absurd.
NIH is a special case of homophilic closure and homophily: similarity is defined by organisational membership and authorship, not only demographics or rank. “We didn’t invent it” becomes a proxy for not trusting it.
In software systems
Every dependency is suspect until rewritten in-house. Open-source replacements are rejected for “not fitting our stack” when the fit problem is identity. Platform teams ignore internal tools built by sister divisions. Acquisitions freeze the acquired codebase out of the roadmap — technical NIH as territorial defence.
In human organisations
Consultants deliver tier-2 findings that die in the drawer; the same conclusions re-emerge months later labelled internal strategy. Benchmarking visits produce nodding politeness and no adoption. R&D reinvents commodity capabilities because procurement and pride block buy.
NIH pairs with homophilic dismissal: the bearer is wrong because they are external; the content never reaches tier review.
In socio-technical systems
Vendor scores and community plugins rank below home-grown alpha because reputation systems overweight local authorship. Inner-source programmes fail when contribution from “not our team” is second-class in review queues.
Counter direction
Judgment infrastructure records provenance separately from tier: who said it, where it came from, and how strongly it is supported must not collapse into one “not invented here” veto. Cross-boundary commitment boundary trials — adopt external design as committed experiment with falsify-only review — defeat NIH without banning local innovation.