Gender in English is quite different to many languages because objects are generally always treated as neutral, and animals are mostly treated as neutral, even when they have a gender. The result is that the pronouns “he” and “she” are almost always used to refer to people, and have implications of personification when used to refer to animals. Here’s a few notes and examples to discuss this point more clearly:
Why ‘he’ and ‘she’ are typically used for people
Grammatically, English language normally refers to animals and objects in neutral terms. This is standard for objects, which have no sexual genders, and are always its. Even objects which are labelled as gendered, such as male and female plug connections (because one has a point going out, the other a connection going in) are referred to as it.
For animals, genders may be appropriate when the gender is known, but it is standard to refer to general animal words. Without further information, cat, dog, giraffe, platypus – these are all neutral. Only animal terms that tell us the sex of an animal can define it as a he or she, such as lioness for female lion. Because we use general terms more than specific gendered terms, as mostly we may not be aware of or care about animal genders, it’s most common to refer to animals as it.
For people, we generally understand immediately if someone is male or female, if not by appearance then by the way they are described – gender neutral language regarding people is quite rare in English. People are often referred to, for example, as man or woman, rather than person. Gendered pronouns are therefore most common talking about people, and therefore generally associated with people.
The result is that most English speakers associate he and she with human traits, and consider it to be impersonal, or like an object. Referring to an animal as he or she might be considered giving it human qualities, while referring to a person as it would be dehumanising and even offensive, even if the gender is unclear (ask someone “What’s its name?” about their baby, and they may get upset).
When to use he, she and it for animals and objects
Animals clearly do have sexual genders though, so it is still appropriate to use he and she to describe the animal when we know what that gender is. With that in mind, though, it does sound strange to refer to an animal as he or she when you don’t know the gender. So to be safe, use it for animals unless the gender is clear.
One area that gendered pronouns are common for animals is when we talk about our pets. Pets will always have a known (or at least decided!) gender, and people use gendered pronouns to talk about their pets as an acknowledgement of personality and a personal connection. Like with babies, you will be expected to talk about someone’s pet with a gendered pronoun.
For objects, there are few exceptions when he or she is appropriate. The most common, and hopefully obvious, occasion when this is appropriate is when an object represents something that is clearly gendered. It is okay to refer to a female doll as she, for example. Or if you refer to a deliberately personified object – such as if you have drawn a smiley face on something! In these respects, bare in mind than he and she denote personality – they are used to personify. Otherwise, he, she and it always refer to sexual gender, not gendered nouns.