They can learn hundreds of words, count to five and read humans like a book, so why do we struggle to understand them? Scientists reveal the truth about our pets – and whether they ever feel guilty for eating our slippers

The thing that made me think my dog may be a genius was the word monkey. We’d developed a game where I’d hide her monkey toy – a sad, lifeless being, long lobotomised by my golden retriever puppy – and, when I asked her to find it, I realised she could differentiate the word monkey from other objects. A woman in the park had a similar story. On holiday in an unfamiliar cottage, she had misplaced the car keys. After hunting for them for over an hour, her dog, a border collie, overheard her and her husband talking about it, recognised the word “keys” and immediately went and found them.

So maybe my dog, Rhubarb, isn’t a genius after all. Dogs, says Vanessa Woods, director of the Puppy Kindergarten project at Duke University in North Carolina, US, and writer of several books including Puppy Kindergarten: The New Science of Raising a Great Dog, can know hundreds of words for objects. “Over 1,000, probably,” she says. “And actually it’s more interesting than that, because they learn words the way children learn words, and that’s not by repetition.” Psychology professor Juliane Kaminski showed back in 2004 that a dog called Rico (another border collie), could learn, as children do, by inference – he didn’t need to know the name of a new toy, he could work it out by excluding the toys he did know the names of.

Pop’s top matriarch is finally getting the credit she’s due. She talks about her shock diagnosis, conspiracy theories about her family, and the Instagram posts that get her in trouble with her kids

It’s been a decade since Tina Knowles started dictating her life story into her phone for her grandchildren and future great-grandchildren. She wanted them to know their history – her early life and world were so different from theirs, she might as well have been from another planet. Knowles, the youngest of seven, born to a docker and seamstress, grew up poor in segregated Texas. Her grandchildren, born to Knowles’s superstar daughters, Beyoncé and Solange, are growing up in Los Angeles and New York with unimaginable wealth, but under unimaginable scrutiny.

A couple of years ago, Knowles started writing a book that was supposed to be her behind-the-scenes take on the outfits she had created for her daughters’ music careers – the dazzling triple-denim looks she had cobbled together from fabric remnants and army-surplus stores, with almost no budget, for Beyoncé’s group Destiny’s Child in the 1990s. She was still improvising costumes once Beyoncé had gone solo and could have her pick of designer clothes; even the singer’s spectacular recent Renaissance tour had input from her mother.