Forget about bra sizes and six packs: from now on its our IQ that will be key in finding a mate. According to American trend spotter Marian Salzman, for the next decade, a healthy brain, boosted by exercise and supplements, will be the best way to attract the opposite sex and, more generally, make a good impression on others. So after all the fuss and focus on physical bling and beauty during the Noughties, it seems we’ll be taking a look on the inside at last.

Today’s picture is by an artist who knew, way ahead of his time, that our minds and morals were the most interesting things about us. It’s Leonardo da Vinci’s portrait of Ginevra de’ Benci (1474) which he painted when he was 22.

So how does Leonardo make a painting of someone’s outside appearance and yet still focus on her inside qualities? Well, first he has to bring her to life, or else we wouldn’t believe in her. He convinces us with a few subtle techniques. For instance, he places her body in a 3/4 pose (it’s 3/4 of the way turned towards us) while her head is almost fully frontal (looking directly at us). So unlike earlier portraits, where lumpen sitters tended to look stiff and dead, Ginevra is twisting and seems to be actively turning to look at us. Next he creates this incredible luminous-looking skin with a technique he pioneered called chiaroscuro, which uses gradations in tone to suggest light and shade and thereby volume. From her eyes, down her nose, over her cheeks and onto her chin, the color changes in the oily pink paint are so subtle that the surface becomes almost like real skin. Then there’s her hair; with a super fine brush he’s created individual strands slicked down her head and curling at her hairline. Realistic also is the detail of her dress: lacing, brocading and a diaphanous material at her neck all add to the realism.

But so far we’re still in superficial mode, we’ve only looked at what’s on her outside. So let’s consider the evidence that Leonardo cared about her inner qualities and wanted to bring that out in the painting. We need proof that someone’s inner qualities can grab us as much as their outer assets.

So here’s where it gets interesting. What do you think we notice first about this picture? What’s the first thing that catches you when you stand face to face with the work? These days we don’t bat an eyelid if a person in a photograph or a painting looks directly at us and meets our gaze. But this is 1474 we’re talking, and before this, no other artist had painted a female sitter looking straight out at the viewer. Revolutionary for the time, it’s Ginevra’s eye contact with the viewer that is the single most powerful thing about the picture and key in creating the idea of her independent character and lively mind.

Adding to this, Leonardo has set her features in a particular way to suggest a mood. So he’s gone beyond making her eyes, nose and mouth look individualized to actually place them in such a way as to convey her character. The eyes seem to narrow somewhat and her mouth is set in a line with not a hint of a smile. Is she suspicious, determined or just one tough cookie? Whichever way you choose to interpret this young lady, it’s clear she’s bursting with attitude.

Another strategy that Leonardo used throughout his career was to have settings and surroundings further enhance our sense of the people in his paintings. So in the right middle ground here we have a little landscape, with marshy blue waters and shady trees- some say this moody little scene adds to the ‘moodiness’ we read in Ginevra. There’s also a bush that sprouts behind her head, with lots of dark green leaves spiking the clear sky. That’s a juniper bush, which he’s added as a play on her name (the Italian for juniper, ginepro, is a pun on her name Ginevra).

So Ginevra’s direct gaze, her suggestive expression and her setting all scream character and active mind. Lastly, let’s look at Leonardo’s trump card, the final thing he does to hammer home the point that our inner selves are more interesting and relevant than what people see on the surface. This is the only time in his life that Leonardo painted the back of a picture: on the reverse there’s a wreath of laurel, palm and juniper all bound by a scroll that says VIRTUTEM FORMA DECORAT. This is Latin for ‘beauty adorns virtue’, i.e. pretty on the outside should only be seen as a reflection of pretty on the inside. So in Ginevra’s case, shown here at 16 on the occasion of her betrothal or marriage, her physical beauty is held up as a mirror to her fine mind and morals.

Leonardo is perhaps our favorite Old Master: he speaks to us because he was born ahead of his time and had a pioneering mind that we can still identify with. But I have to say, I’m surprised to find him leading the way even here, in matters of appearance and personal grooming versus how we cultivate our inner selves. I think he’s telling us that it’s alright to primp and preen, to go to the gym and make an effort, just as long as we also focus on the inside, exercise our minds and practice our morals. As those are the things that really make an impression.