It's a question you might never have considered before - why do older siblings do better on IQ tests than their younger counterparts?
But if you want to get into Oxford's experimental psychology program, you'd better be prepared to answer.
The university has released a series of questions from tutors who conduct the infamous interviews, revealing the complex problems in everything from mathematics to medicine used to spot the sharpest candidates.
For students hoping to be accepted into Oxford's most competitive programs, the interviews can be a dreaded obstacle.
They represent 'an entirely new experience for most students,' and are often surrounded by misunderstanding, according to Dr Samina Khan, Director of Admissions and Outreach at Oxford.
Instead, the interviews are intended to allow students to show off their interest and ability in a given subject, regardless of their background or prior opportunities, Khan says.
To put some of the fears to rest, Oxford has released five sample questions from the interviewers themselves - and, they've revealed the best ways to respond.
Q: What makes a novel or play 'political'?
According to interviewer Helen Swift, of St Hilda's College, this is a Modern Languages question that could come from a student's own statement on their engagement with literature and culture of the language they want to study.
After citing a specific work, the conversation may broaden to address the student's conceptual understanding.
"So, in posing the overall question 'what makes this political?' we'd want the candidate to start thinking about what one means in applying the label: what aspects of a work does it evoke?," Swift explains.
"Is it a judgement about content or style? Could it be seen in and of itself a value judgement? How useful is it as a label? What if we said that all art is, in fact, political? What about cases where an author denies that their work is political, but critics assert that it is - is it purely a question of subjective interpretation? And so on."
According to Swift, a strong candidate would be ready and willing to develop their ideas in conversation. And, changing their mind during the discussion to contradict an earlier point is fine.
Q: About 1 in 4 deaths in the UK is due to some form of cancer, yet in the Philippines the figure is only around 1 in 10. What factors might underlie this difference?
This question, provided by Chris Norbury of the Queen's College, could be given to a student applying to the Medicine program.
And, it's one which has 'no single 'correct' answer,' Norbury says, instead opening up the door for the conversation to take a particular direction based on the candidate's interests.
'Some candidates will ask useful clarifying questions, such as 'Where do these data come from, and how reliable are they?', or 'What is the average life expectancy in these parts of the world?'' Norbury says.
"Some candidates will seize on the idea that various aspects of the typical lifestyle in the UK are inherently unhealthy, which can make for an interesting discussion in itself.
"Others, especially if they appreciate that life expectancy in the Philippines is substantially lower than in the UK, will realise that other causes of death are more common in the developing world, and that this is the major factor that gives rise to the difference alluded to in the question.
"This probes selection criteria including problem-solving, critical thinking, intellectual curiosity, communication skills, ability to listen and compatibility with the tutorial format."
Q: What exactly do you think is involved in blaming someone?
This question would be presented to an applicant for the Philosophy, Politics, and Economics program, along with other philosophy courses, according to interviewer Ian Philips, from St Anne's College.
'With a question like this we're not looking for a right answer but instead whether the candidate can be creative in coming up with examples and suggestions, and can think critically and carefully through their implications,' Norbury says.
"So, for example, many candidates start out by suggesting that for A to blame B, A would have to think that B had done something wrong. Many might also make the point that B needn't actually have done anything wrong.
"We can use this opening suggestion to consider a simple theory of blame: blame is just thinking that someone has done something wrong. When this is put to candidates, most recognize that blame seems to involve more than this.
"This shows their capacity to evaluate a proposal, and we'll typically ask them to illustrate their verdict with a counter-example: a case where someone thinks someone has done something wrong but doesn't blame them."
The candidates might then be encouraged to offer more sophisticated proposals on the nature of blame, Phillips says, which can be put to the test through counter-examples.
Q: Imagine a ladder leaning against a vertical wall with its feet on the ground. The middle rung of the ladder has been painted a different colour on the side, so that we can see it when we look at the ladder from the side on. What shape does that middle rung trace out as the ladder falls to the floor?
According to Rebecca Cotton-Barratt, of Christ Church, this maths question tests abstract thinking - and, the answer is 'typically the opposite of what they expect."
"I'd initially ask the candidate what shape they think will be formed, and then ask them how they can test this hypothesis," Cotton-Barratt says.
"They might initially try sketching the ladder at different stages - this is fine, but ultimately what we want is something that we can generalise and that is accurate (you can't be sure that your drawing is that accurate, particularly when you're making a sketch on a whiteboard and don't have a ruler). So eventually they will fall back on maths, and try to model the situation using equations.
"If they get stuck we would ask them what shape the ladder makes with the wall and floor, and they'll eventually spot that at each stage the ladder is forming a right-angled triangle. Some might then immediately leap to Pythagoras' Theorem and use that to find the answer (which is that it forms a quarter circle centred on the point where the floor meets the wall).
Q: A large study appears to show that older siblings consistently score higher than younger siblings on the IQ tests. Why would this be?
This question would be asked to students looking to join Experimental Psychology, according to Kate Watkins, from St Anne's College.
Watkins says, "This is a question that really asks students to think about lots of different aspects of psychology, and we guide students when discussing it to think about both scientific factors such as maternal age (mothers are older when younger siblings are born - could that play a role?) and observational analysis about how birth order might affect behaviour and therefore performance on IQ tests."
The interviewers will add more information as the students attempt to use reasoning to answer the question, leading them to think about the dynamics that may come into play for an older sibling.
"Eventually most students arrive at the conclusion that being an older sibling and having to teach a younger sibling certain skills and types of knowledge benefits their own cognitive skills (learning things twice, in effect)," Watkins continued.
"But there isn't really a 'right' answer and we are always interested to hear new explanations that we haven't heard before. What we are interested in is the kinds of reasoning students use and the questions they ask about the study - what it takes into account, what it might not - that tells us about their suitability for the course.
"And of course it doesn't matter if you have a sibling or not - though depending on family dynamics, that can add an interesting twist to the conversation!"