Many people have a type - and when they try to describe it, will often refer to physical characteristics like blue eyes or brown hair.
But for others, known as sapiosexual, their type is cerebral - that is to say, they are sexually attracted to highly intelligent people, viewing brains as the most important quality in a mate.
And it appears sapiosexuality is on the rise, with people taking to platforms like TikTok to talk about how hot under the collar a high IQ can make them, with the sapiosexual hashtag reaching almost 4.5 million views on the platform.
However, the label is not without controversy. To understand why, it's important to understand exactly what sapiosexuality is.
Barbara Santini, a psychologist and sex advisor at Peaches and Screams, told FEMAIL: 'Sapiosexuality has become a popular term in recent years to describe individuals who are primarily sexually attracted to intelligence or intellect.
'While physical attraction may still play a role in any relationship, a sapiosexual person places a greater emphasis on mental connection and intellectual compatibility.'
She added: 'Intelligence is the top priority for a sapiosexual, and they place less emphasis on superficial qualities.'
Psychiatrist and Medical Educator Dr Ramya Mohan added: '[Sapiosexuality] is a relatively new terminology that has broad connotations based on context. It is a term that has become more colloquial over the past couple of years or so.
'It is worth noting that sapiosexuality can be interpreted broadly, encompassing everything from a preferential seeking of intelligence in relationships or partnerships to a driving sexual and almost obsessional need for intelligence in a partner (above all other physical, emotional, gender-based and orientation-based attributes, preferences, and needs).'
It's difficult to assess exactly how many people fall under this banner - after all, most people want an intelligent partner.
However, according to the authors behind a 2018 study published in the journal Intelligence, a much smaller proportion are specifically sexually aroused by intelligence.
The researchers, from the University of Western Australia, noted that the value of high intelligence extends beyond what it offers in terms of a mate's potential when it comes to basic survival and parenting.
And then some people rate being brainy so highly, that a high IQ can induce sexual arousal above and beyond any other attribute - these people could be described as sapiosexual.
Their findings suggest that between one to eight per cent of people aged 18 to 35 may be sapiosexual.
So while many lonely hearts will seek an intelligent other half, not so many of them will be sexually aroused by a potential partner's IQ over and above any other qualities they may possess.
So, do you fall into this category? And what signs may you look out for? According to expert Hope Flynn, who is head of content at sexual wellness brand IPlaySafe and a self-confessed sapiosexual, there are a number of pertinent signs.
She told FEMAIL: 'The first and most common sign of someone being a sapiosexual is that they are aroused by intelligence more so than physical attraction. Intelligence is the essential ingredient for the arousal of a sapiosexual.'
They prefer intelligence to everything, it outweighs what the person does for a living, their other interests or how much money they make, she added.
Among the other signs she noted, were disliking small talk, explaining: 'In any relationship conversation is key but sapiosexuals desire a deeper level of knowledge from their partner. Being able to hold deep and meaningful conversations is key to a sapiosexual - a surface level of knowledge just won’t suffice.'
An interesting sign Hope listed was that sapiosexuals are 'more drawn to people who can rationalise their feelings and communicate them without exploding or flying off the handles when faced with difficult situations'.
She noted: 'They cannot tolerate people who unravel easily.'
Interestingly, when it comes to social media, Hope suggests that sapiosexuals are more likely to care about your Instagram caption than the photo itself - which is related to wanting to learn.
In fact, she said, they may even seek out people who they find to be smarter than them because they always want to learn and grow.
'They are obsessed with his/her intellect and thoughts and want to hear more about them as it helps to enrich their knowledge,' Hope added.
In a similar vein, they have an intellectual thirst, and are turned on by smart perspectives and intelligent answers.
If you find attraction tends to grow over time, this could be a sign of sapiosexual tendencies.
'As sapiosexuals like to dig deep into intellect they feel more attracted to a person gradually over time,' said Hope.
'Experiencing someone’s wit, thoughts, emotional intelligence and observing how someone resolves conflicts are the things that are a massive turn on.'
Finally, she said, sapiosexuals admire others who have a passion for knowledge, because it aligns with their personal desire to be expanding and learning at all times.
Dr Ramya Mohan agreed, adding: 'If a potential partner preferentially or wholly observes, remarks on, or compliments your intelligence, knowledge, or quick-witted replies, you may be talking to a sapiosexual'
She continued to explain that sapiosexuals tend to 'place high regard and value for these attributes'.
'They tend to focus on (and tend to be attracted/aroused by) intelligent, witty, complex, and lengthy conversations, book or academia-based discussions, deep meanings of the world or life, set morals and a learned demeanour,' Dr Moyan said.
However, while a sexual preference for intelligence may seem benign, it is not without its critics, who have branded it ableist and classist.
As Hope Flynn explained: 'It could be seen to exclude people with learning difficulties or those that come from disadvantaged backgrounds with less access to higher education, travel and technological advancements.'
Furthermore, the term intelligence itself is often used in relation to what we may colloquially consider to be 'book smarts', many of the people who fall into this category are likely to have had access to a better education. For this reason, some argue that the preference can be seen as classist.
'Being a sapiosexual could indicate that someone may only be interested in someone who had the privilege of going to a certain school or obtaining a particular degree,' said Hope.
'It could be interpreted as being quite Eurocentric and devaluing of people without access to the above.'
However, she added: 'I'm a self confessed working class, sapiosexual that believes intelligence is subjective. Intelligence has a lot to do with an individuals morals, values, political and religious beliefs.
'There are also so many forms of intelligence to be considered when wondering if you’re a sapiosexual, such as emotional intelligence, spiritual intelligence and so on...if someone has a desire and thirst for knowledge...this will be apparent regardless of the class they were born into.'
