AI intelligence shouldn't be measured with a single metric like IQ. AIs exhibit "jagged intelligence," being superhuman in specific domains (e.g., mastering 200 languages) while simultaneously lacking basic capabilities like long-term planning, making them fundamentally unlike human minds.

Instead of a single, generalizable AI, we are creating 'Functional AGI'—a collection of specialized AIs layered together. This system will feel like AGI to users but lacks true cross-domain reasoning, as progress in one area (like coding) doesn't translate to others (like history).

Language is just one 'keyhole' into intelligence. True artificial general intelligence (AGI) requires 'world modeling'—a spatial intelligence that understands geometry, physics, and actions. This capability to represent and interact with the state of the world is the next critical phase of AI development beyond current language models.

Progress towards AGI is not a smooth climb. Models exhibit "spikiness"—they can perform at a world-class level on one narrow domain but degrade to a "bad high school student" with slight perturbations. This non-intuitive generalization makes their capabilities uneven and unpredictable.

Demis Hassabis explains that current AI models have 'jagged intelligence'—performing at a PhD level on some tasks but failing at high-school level logic on others. He identifies this lack of consistency as a primary obstacle to achieving true Artificial General Intelligence (AGI).

The current focus on pre-training AI with specific tool fluencies overlooks the crucial need for on-the-job, context-specific learning. Humans excel because they don't need pre-rehearsal for every task. This gap indicates AGI is further away than some believe, as true intelligence requires self-directed, continuous learning in novel environments.

Demis Hassabis identifies critical capabilities missing from today's AI systems. The biggest hurdles are continual learning (the ability for a trained model to learn new things without retraining) and hierarchical, long-term planning. This suggests that simply scaling current architectures may not be enough to achieve AGI.

A practical definition of AGI is its capacity to function as a 'drop-in remote worker,' fully substituting for a human on long-horizon tasks. Today's AI, despite genius-level abilities in narrow domains, fails this test because it cannot reliably string together multiple tasks over extended periods, highlighting the 'jagged frontier' of its abilities.

The central challenge for current AI is not merely sample efficiency but a more profound failure to generalize. Models generalize 'dramatically worse than people,' which is the root cause of their brittleness, inability to learn from nuanced instruction, and unreliability compared to human intelligence. Solving this is the key to the next paradigm.