The problem with all of this is that using these kinds of emotional reactions to evaluate research can lead to making some significant errors that can cause rea

The problem with all of this is that using these kinds of emotional reactions to evaluate research can lead to making some significant errors that can cause real harm. As an example, facilitated communication was once touted as a way in which non-verbal autistic people could communicate with the outside world (https://en.wikipedia.org/wiki/Facilitated_communication https://en.wikipedia.org/wiki/Facilitated_communication). The facilitators thought it worked. Parents thought it worked. It felt great to be able to talk to your kids who you could never talk to before. The problem is, it was complete bunk. If you did any kind of actually blinded test, such as showing one picture to the facilitator and another to the subject, they would write out what the facilitator saw. The facilitators themselves weren't even aware they were doing this. But on the basis of this completely pseudoscientific method, there had been parents who had been accused of sexual assault of their children and kicked out of their house because of it, when in reality the abuse had just been imagined by the facilitator. Emotions are definitely important in communication, and communicating emotions with animals is definitely possible. But there are real reasons for demanding better evidence before claiming that you are interpreting language on behalf of some other person or animal. > quantifiable, numerical data we are used to in engineering and computer science You make it sound like quantifiable, numerical data is a fairly niche thing, but of course it's used in pretty much every field of scientific inquiry. Science is the practice of using the best tools we have to better understand the world around us. Subjective description of interactions with the world around us is just a very basic baseline from which to start inquiry, not something that you can say has led to meaningful results. In this case, it doesn't even necessarily require substantial numerical data to evaluate these claims; just basic blinding procedures, like evaluating the results of Koko describing something that she saw that her handler did not, and getting some basic statistics over a number of interactions to see if they do better than chance.