Wie viel Sex passt in ein Einmachglas?: Was die Mathematik über unser Liebesleben verrät

by Clio Cresswell

Für Mathematik interessiert sich nur eine Minderheit der Bevölkerung -- Sex dagegen zählt nicht ohne Grund zu Googles beliebtesten Suchbegriffen. Mathedozentin Clio Cresswell entschied sich (wenn auch nicht als erste), beides zu verbinden, damit ihre Studenten besser bei der Sache blieben. Sie behauptet: „Sex ist im höchsten Maße mathematisch.“ Diese These, die zunächst aberwitzig anmutet, beweist sie auf den folgenden Kapiteln mit Humor und vielen interessanten Fakten. Und man begleitet sie gerne auf Ihrer Suche nach Gesetzmäßigkeiten in dem, was wir „Leben“ nennen.

Herausgekommen ist ein Werk, das eher in den Bereich Biologie gehört als in die Mathematik. Man erfährt eine Menge Faszinierendes über Beziehungen und Fortpflanzung -- zum Beispiel über Muster und Zyklen in Partnerschaften, die Chancen einer Ehe, Theorien über Sex nach der Hochzeit und die Schwankungen des Testosteronspiegels --, aber wer seine Kenntnisse in Mathematik spielerisch erweitern will, der sucht sich besser ein anderes Buch. Die komplizierten Formeln, die Cresswell abbildet, werden nicht erklärt, sie dienen, wie die Autorin auch im Vorwort erwähnt, nur als Dekoration. Nur der Fachmann wüsste etwas mit ihnen anzufangen. Allerdings machen sie (zum Beispiel) deutlich, wie komplex „die Beziehungen zwischen Hirn und Schwanz eines Mannes gestrickt ist“ -- die erwähnte Testosteron-Gleichung geht über eine halbe Seite und sieht ausgesprochen hübsch aus.

Überzeugend demonstriert Cresswell jedoch, dass an der Schnittstelle von Bio und Mathematik Aspekte von Liebe und Sexualität deutlich werden, die sonst verborgen geblieben wären. Wer hätte gedacht, dass mathematische Prognosen in einem so unwissenschaftlichen Bereich wie Liebe besser sein können als Astrologie oder Lebenshilfe-Kolumnen? Zum Beispiel gibt eine Formel die Antwort auf die alte Frage, wie viele Liebhaber man ausprobieren sollte, bevor man sich mit dem Gefühl, eine gute Wahl getroffen zu haben und nichts verpasst zu haben, zufrieden geben kann? Die Antwort: Ein Dutzend. Das bietet eine genau berechnete Erfolgsgarantie von 75 %. -- Nina Hesse

Genres: Mathematics, Sexuality, Science, Nonfiction

191 pages, Paperback

First published September 1, 2003

Reviews

[okyrhoe · Rating 3 out of 5]

In the beginning I was irritated by Cresswell's somewhat contrived conversational style (as if she's the instructor speaking to students who have to be lured into finding an interest in mathematics) but gradually I ignored that in favor of the topics regarding human relationships.

Eg.:
-- Why is it biologically 'sensible' that the human male produces millions of sperm daily while a woman releases only one egg a month?
-- Why are there more than 2 sexes in other species? And what is likely to happen to the 2 human sexes, over the passage of biological time?
-- Is there a statistical and/or descriptive differentiation in the experience of orgasms between men and women?
-- Is there a formula for evaluating happiness? What's more likely to contribute to a more fulfilling life - seeking personal happiness or achieving group happiness?
-- How much should one compromise in a marriage?*
-- How many behavioral characteristics should we take into consideration when evaluating our compatibility with a romantic/sexual partner? Is there a formula for deducing who is the most suitable mate?
-- How many persons should you date before concluding you've found 'the one,' or at least the 'best' person who's liable to reciprocate your affections?**

I find that this perspective of looking at human (emotional & sexual) relationships is refreshing, especially in the wake of the countless self-help relationship books that advise us to work and work on improving our lackluster selves, or our lackluster relationships, in the hope of improving our 'odds,' rather than guiding us towards identifying the partner who is compatible in the here and now.

Unfortunately Cresswell is not as good a writer as she is a summarist of other people's theories. And she has an annoying style of simplifying the mathematical formulas, usually by not identifying the variables of the equations. That's a shame, because it suggests that Cresswell assumes her readers are mathematically challenged, incapable of understanding the science involved. At least she could have included a detailed presentation of the formulas in a final chapter for optional reading.

- - -

* Spouses that have a low negativity threshold (expressing negative feelings immediately, rather than keeping quiet and empathizing with their partner) remain married longer.
**If you experiment with 12 persons and then pick what Cresswell calls the 'next best' that most resembles the 'best' of the first dozen, then you have a 75% chance of selecting a suitable person for settling down with.

[Robert · Rating 2 out of 5]

Too light on the mathematics. In a brave attempt to make math appealing to those who aren't interested in the subject, the author avoids any of the detail that would make this book appealing to those who are interested in the math.

Because it lost my interest early, I didn't read very far into it. I like the premise of showing how mathematical models are useful in understanding complex patterns in life, love, and even sex. But the book tells the reader how math could help them understand these patterns, rather than showing them by actually walking them through the details.

[Monstah · Rating 1 out of 5]

The other reviews pretty much sum it: tries to make math interesting to those who don't care about it by mentioning sex, and then doesn't go any deeper for anyone who's interested.

[DG Vinay · Rating 4 out of 5]

This is a fun book to link mathematics and all the different portions of your dating and relationship life which is surprisingly useful and can be applied in your own life for good

[Anna · Rating 3 out of 5]

I quite enjoyed some parts of the book. Some parts were a bit too much of, um, math and formulas that went a bit beyond my skills, but there were a bunch of interesting parts to use as parts in cocktail discussion (or whatever equivalent I ever end up going to).

Some parts could have been more present, e.g. the complexity of orientation (I joke that the bisexuals have 100 % more potential catches than 'retrosexuals' or monosexuals..). There could be some math (research and statistics) on the potentials for which orientation would yield best results... (Why not? if among the examples was how many potential candidates to 'test drive' before settling the first one that exceeds the desired or minimum criteria, at least the orientation parts would help maximize the results)

I've always been curious about why there are only two sexes, but the math around the amount of genders didn't quite square it all. If there were let's say three genders, why would two be needed for repros? How about one (or two, or three) being autoreproductive? Or requiring all three genders sexes? Wait, how about considering the third gender as third sex instead? (Or how about the whatsitcalled historic tribe somewhere that considered there to be seven genders?) Or if there were more than three genders, why not need all n or n-1 or n-2 genders to participate (and with various matrices on potential combinations)? (can perhaps guess my favorite parts of math included statistics for all the possibilities and what they can prove?)

http://www.bookcrossing.com/journal/3...

[Eva Filoramo · Rating 1 out of 5]

Deludente. Già il titolo non lasciava presupporre gran ché di buono - troppo commerciale. Davvero ottimi, al contrario, gli spunti di argomenti, che però sono tutti da approfondire perché l'autrice ogni tanto butta lì qualche equazione ma, per chi di matematica ne sa un po', la cosa è piuttosto frustrante, dal momento che le equazioni non soltanto non sono commentate, ma neppure si comunica a cosa corrispondano le variabili!
Fortunatamente c'è grande attenzione nel citare i nomi e cognomi di chi, in particolare, si è occupato dei vari problemi; con l'aiuto di internet e di un accesso ai db delle riviste specializzate, pertanto, è possibile approfondire.
La traduzione e la redazione italiana sono veramente trascurate (basti pensare al Max Plance Institut) e anche la scrittura, se forse nell'originale inglese può essere divertente, in italiano è a tratti davvero patetica. Peccato.

[Riccardo · Rating 2 out of 5]

Da prendere per quello che è, una solenne americanata. Le formule son messe lì per generare meraviglia e spavento, più che per spiegarle, e da matematico l'ho trovato un trucchetto davvero penoso. Stile americano da motivatore visto mille altre volte in mille altri saggi del genere. Diciamo "passabile", se non avete di meglio da leggere, visto che comunque contiene anche degli spunti interessanti.

[Celine Spiteri · Rating 5 out of 5]

Anyone can solve a problem after hitting the sack!! Do try it.