Inferential reasoning in non-humans: a critical analysis of experimental evidence

Is human language necessary for logical reasoning? Multiple studies address this by showing animals a bait hidden in either of two inverted cups, briefly lifting one exposing its content and then letting subjects choose. Consistent preference for the baited container is interpreted as evidence of inferential reasoning by exclusion (“ if the bait is not here, it must be there ”). More complex variations invoke metacognitive revision of hypotheses. We show that these protocols do not demonstrate logical reasoning. Instead, each event-stimulus elicits different actions and this suffices to choose correctly between them. We demonstrate this with experimental starlings and argue that other species may show similar behaviour, highlighting the need for careful controls when attributing high-level mental capacities such as reasoning or causal understanding.