Your Dominant Side Might Determine the Way You Kiss


Our bodies are remarkable things. All day long, they keep our hearts pumping and our lungs filling with air. They do all this without any instruction from us. But they do other things, too—things we don’t even realize we’re doing. Take, for example, a new study published in Nature Scientific Reports that finds people subconsciously tilt their head toward their dominant side when leaning in for a kiss.

We call this dominance right- or left-handedness, but it actually runs through our entire body, including the direction we automatically turn our heads. For most people, that means looking to the right.

"Head turning is one of the earliest biases seen in development," lead author Rezaul Karim of the University of Dhaka said in a statement. "Even in the womb, a preference for turning the head to the right is observable before that of favoring the right hand or foot. Whether this fundamental bias is innate and extends into adulthood is a lingering question for neuroscience and psychology."

One way to find out is by watching people kiss. Numerous experiments have been conducted to determine which way people tilt their heads, and they have concluded that we lean to our dominant side. But those experiments all took place in Western countries, and they were either conducted in public places like airports or in a lab—hardly places where participants might feel at home.

To test the premise in a more comfortable setting, Karim and his colleagues recruited 51 married couples in Bangladesh and invited them to start keeping track of their kisses in the privacy of their homes. Each participant received two questionnaires: one to determine their dominant side and another to record their head-tilt tendencies during kissing.

The results looked quite similar to those of earlier studies elsewhere in the world. When initiating a kiss, most people leaned right, but lefties turned left.

Things looked slightly different on the receiving end of a smooch. Regardless of their dominant hand, kiss-ees were most likely to tilt their heads in the opposite direction as their partners’, because, as we all know (and the questionnaires confirmed), it feels weird to go the other way.

Commonsense though they may seem, these findings do still need to be validated with more research. The in-home kissing experiment was one very small study among one very specific group of people, many of whom were friends of the researchers.

But co-author Michael Proulx of the University of Bath in the UK said the private nature of the experiment allowed participants to act naturally, and that the results of this natural behavior have "…implications for all people. Prior works could not rule out cultural learning due to having Western samples," he said. "It turns out, we as humans are similar even if our social values differ."

Fossilized Fat Shows 550-Million-Year-Old Sea Creature May Have Been the World's First Animal

Ilya Bobrovskiy, the Australian National University
Ilya Bobrovskiy, the Australian National University

A bizarre sea creature whose fossils look like a cross between a leaf and a fingerprint may be Earth's oldest known animal, dating back 558 million years.

As New Scientist reports, researchers from the Australian National University (ANU) made a fortunate find in a remote region of Russia: a Dickinsonia fossil with fat molecules still attached. These odd, oval-shaped creatures were soft-bodied, had rib structures running down their sides, and grew about 4.5 feet long. They were as “strange as life on another planet,” researchers wrote in the abstract of a new paper published in the journal Science.

Another variety of fossil
Ilya Bobrovskiy, the Australian National University

Although Dickinsonia fossils were first discovered in South Australia in 1946, researchers lacked the organic matter needed to classify this creature. "Scientists have been fighting for more than 75 years over what Dickinsonia and other bizarre fossils of the Edicaran biota were: giant single-celled amoeba, lichen, failed experiments of evolution, or the earliest animals on Earth,” senior author Jochen Brocks, an associate professor at ANU, said in a statement.

With the discovery of cholesterol molecules—which are found in almost all animals, but not in other organisms like bacteria and amoebas—scientists can say that Dickinsonia were animals. The creatures swam the seas during the Ediacaran Period, 635 million to 542 million years ago. More complex organisms like mollusks, worms, and sponges didn’t emerge until 20 million years later.

The fossil with fat molecules was found on cliffs near the White Sea in an area of northwest Russia that was so remote that researchers had to take a helicopter to get there. Collecting the samples was a death-defying feat, too.

“I had to hang over the edge of a cliff on ropes and dig out huge blocks of sandstone, throw them down, wash the sandstone, and repeat this process until I found the fossils I was after,” lead author Ilya Bobrovskiy of ANU said. Considering that this find could change our understanding of Earth’s earliest life forms, it seems the risk was worth it.

[h/t New Scientist]

The Weird, Disturbing World of Snail Sex


Romance is rare in the animal kingdom. Instead of wooing their partners before copulating, male ducks force themselves onto females, depositing genetic material with spiky, corkscrew penises. Then, there's tardigrade sex, which is less violent but not exactly heartwarming. Females lay eggs into a husk of dead skin. The male then ejaculates onto the eggs while stroking the female, and the whole process can take up to an hour.

But you can't talk about disturbing mating rituals in nature without mentioning snails. If you're unfamiliar with snail sexuality, you may assume that snail sex falls on the vanilla side: The mollusks, after all, are famous for being slow-moving and they don't even have limbs. But if you have the patience to watch a pair of snails going at it, you'll notice that things get interesting.

The first factor that complicates snail sex is their genitalia. Snails are hermaphrodites, meaning individuals have both a male set and female set of parts, and any two snails can reproduce with each other regardless of sex. But in order for a couple of snails to make little snail babies, one of them needs to take on the role of the female. That's where the love dart comes in.

The love dart, technically called a gypsobelum, isn't exactly the Cupid's arrow the name suggests. It's a nail-clipping-sized spike that snails jab into their partners about 30 minutes before the actual sex act takes place. The sliver is packed with hormones that prepare the receiving snail's body for sperm. Depending on the species, only one snail might release the dart, or they both might in an attempt to avoid becoming the female of the pair. You can watch the action in the video below.

For sex to be successful, both snails must insert their penises into the other's vaginal tracts at the same time. Both snails deposit sperm, and the strength of the love dart ultimately determines whether or not that sperm fertilizes their partner's eggs.

That's assuming the snail survives the little love-stab. In human proportions, the love dart is the equivalent of a 15-inch knife. Fortunately, snails are resilient creatures, and gastropod researcher Joris Koene tells KQED he's only ever seen one snail die from the transfer.

Snails also have a way of making it up to their partners after skewering them with a hormone stick. Their sperm deposit contains a dose of fortifying nutrients, something scientists refer to as a nuptial gift. It may not equal the energy expended during sex, but its enough to give them a small post-coital boost.