First AI Winter
1970–1979 · 3 milestones
Reality failed to match the hype. Funding dried up, criticism mounted, and AI entered its first period of disillusionment.
Milestones
Perceptrons: The Book That Killed Neural Networks
Minsky and Papert published 'Perceptrons,' mathematically proving that single-layer perceptrons could not solve the XOR problem or other non-linearly separable tasks. While technically correct, the book was widely interpreted as proving neural networks were fundamentally limited — though multi-layer networks could solve these problems.
The Lighthill Report
British mathematician James Lighthill published a devastating critique of AI research, concluding that the field had failed to deliver on its promises. 'In no part of the field have the discoveries made so far produced the major impact that was then promised.' The report led to massive funding cuts for AI research in the UK.
Backpropagation Discovered (Initially Ignored)
Paul Werbos described the backpropagation algorithm in his PhD thesis — a method for training multi-layer neural networks by propagating errors backward through the network. However, in the anti-neural-network climate of the 1970s, the work went largely unnoticed.