Conditionals in natural language are central to reasoning and decision making. A theoretical proposal called the Ramsey test implies the conditional probability hypothesis: that the subjective probability of a natural language conditional, P(if p then q), is the conditional subjective probability, P(q/p). We report three experiments on causal indicative conditionals and related counterfactuals that support this hypothesis. We measured the probabilities people assigned to truth table cases, P(pq), P(p notq), P( notpq) and P( notp notq). From these ratings, we computed three independent predictors, P(p), P(q/p) and P(q/ notp), that we then entered into a regression equation with judged P(if p then q) as the dependent variable. In line with the conditional probability hypothesis, P(q/p) was by far the strongest predictor in our experiments. This result is inconsistent with the claim that causal conditionals are the material conditionals of elementary logic. Instead, it supports the Ramsey test hypothesis, implying that common processes underlie the use of conditionals in reasoning and judgments of conditional probability in decision making.

中文翻译：

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因果条件的概率

自然语言中的条件是推理和决策的核心。一个称为 Ramsey 检验的理论提议暗示了条件概率假设：自然语言条件的主观概率 P(if p then q) 是条件主观概率 P(q/p)。我们报告了三个关于支持这一假设的因果指示条件和相关反事实的实验。我们测量了人们分配给真值表案例的概率，P(pq)、P(p notq)、P(notpq) 和 P(notp notq)。根据这些评级，我们计算了三个独立的预测变量，P(p)、P(q/p) 和 P(q/notp)，然后我们将它们输入到回归方程中，判断 P(if p then q) 作为因变量. 与条件概率假设一致，P(q/p) 是迄今为止我们实验中最强的预测因子。这个结果与因果条件是基本逻辑的物质条件的说法不一致。相反，它支持 Ramsey 检验假设，这意味着共同过程是在推理中使用条件和在决策中对条件概率进行判断的基础。